Re: Python less error-prone than Java

[Kaz Kylheku]

Christoph Zwerschke wrote:
> You will often hear that for reasons of fault minimization, you should
> use a programming language with strict typing:
> http://turing.une.edu.au/~comp284/Lectures/Lecture_18/lecture/node1.html

Quoting from that web page:

"A programming language with strict typing and run-time checking should
be used."

This doesn't prescribe latent or manifest typing, only that there be
type checking.

There is no question that for reliability, it is necessary to have type
checking, whether at run time or earlier.

You can have statically typed languages with inadequate type safety,
and you can have dynamically typed languages with inadequate type
safety.

> Now the same thing, directly converted to Python:
>
> def binarySearch(a, key):
>  low = 0
>  high = len(a) - 1
>  while low <= high:
>  mid = (low + high) / 2
>  midVal = a[mid]
>  if midVal < key:
>  low = mid + 1
>  elif midVal > key:
>  high = mid - 1;
>  else:
>  return mid # key found
>  return -(low + 1) # key not found.
>
> What's better about the Python version? First, it will operate on *any*
> sorted array, no matter which type the values have.

Uh huh! With hard-coded < and = operators, how stupid. What if you want
to use it on strings?

Would that be a case-insensitive lexicographic comparison, or
case-insensitive? How do you specify what kind of less-than and equal
you want to do?

-1 to indicate not found? Why copy Java braindamage induced by an
antiquated form of static typing? The Java version has to do that
because the return value is necessarily declared to be of type integer.


;; Common Lisp
;; Binary search any sorted sequence SEQ for ITEM, returning
;; the position (starting from zero) if the item is found,
;; otherwise returns NIL.
;;
;; :REF specifies positional accessing function, default is ELT
;; :LEN specifies function for retrieving sequence length
;; :LESS specifies function for less-than item comparison
;; :SAME specifies function for equality comparison

(defun binary-search (seq item
  &key (ref #'elt) (len #'length)
   (less #'<) (same #'=))
  (loop with low = 0
and high = (funcall len seq)
while (<= low high)
do
  (let* ((mid (truncate (+ low high) 2))
 (mid-val (funcall ref seq mid)))
(cond
  ((funcall less mid-val item)
   (setf low (1+ mid)))
  ((funcall same mid-val item)
   (return mid))
  (t (setf high (1- mid)))

Common Lisp integers are "mathematical", so the overflow problem
described in your referenced article doesn't exist here.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[Peter Otten]

Kaz Kylheku wrote:

> Would that be a case-insensitive lexicographic comparison, or
> case-insensitive? How do you specify what kind of less-than and equal
> you want to do?

class Key(object):
def __init__(self, value, key):
self.keyval = key(value)
self.key = key
def __lt__(self, other):
return self.keyval < self.key(other)
def __gt__(self, other):
return self.keyval > self.key(other)

items = ["Alpha", "Beta", "Delta", "Gamma"]
print binarySearch(items, Key("DELTA", str.lower)) # 2

You /can/ teach an old duck new tricks :-)

Peter
 

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[Kaz Kylheku]

Ilpo Nyyssönen wrote:
> This is one big thing that makes code
> less error-prone: using existing well made libraries.
> You can find binary search from python standard library too (but actually the 
> API
> in Java is a bit better, see the return values).
> Well, you can say that the binary search is a good example and in real
> code you would use the stuff from the libraries.

The trouble with your point is that Christoph's original posting refers
to an article, which, in turn, at the bottom, refers to a bug database
which shows that the very same defect had been found in Sun's Java
library!

Buggy library code is what prompted that article.

> I'd say it is not
> good example: How often will you write such algorithms? Very rarely.
>
> Integer overflows generally are not those errors you run into in
> programs.

Except when you feed those programs inputs which are converted to
integers which are then fed as domain values into some operation that
doesn't fit into the range type.

Other than that, you are okay!

Like when would that happen, right?

> The errors happening most often are from my point of view:
>
> 1. null pointer errors
> 2. wrong type (class cast in Java, some weird missing attribute in python)
> 3. array/list index out of bounds
>
> First and third ones are the same in about every language.

... other than C and C++, where their equivalents just crash or stomp
over memory, but never mind; who uses those? ;)

> The second
> one is one where the typing can make a difference.

Actually, the first one is also where typing can make a difference.
Instead of this stupid idea of pointers or references having a null
value, you can make a null value which has its own type, and banish
null pointers.

So null pointer errors are transformed into type errors: the special
value NIL was fed into an operation where some other type was expected.
And by means of type polymorphism, an operation can be extended to
handle the case of NIL.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Hostmask matching

[John Machin]

On 4/06/2006 4:45 PM, Nexu wrote:
> On Sun, 2006-06-04 at 06:26 +, Marc Schoechlin wrote:
>> Hi !
>>
>> Nexu <[EMAIL PROTECTED]> schrieb:
>>> I'm trying to write a def to match a string that is an irc hostmask. eg:
>>> [EMAIL PROTECTED]
>>> But using re.search(). I get an error when the string starts with '*'.
>>> What is the best way to solve this?
>> I suppose the problem occurs because you expression is not a valid
>> regular expression.
>>
>> A correct regular expression should look like this:
>> "[EMAIL PROTECTED]"
> Thx for everyones input.
> 
> This solved the problem:
>   host = '[EMAIL PROTECTED]'
>   mask = '[EMAIL PROTECTED]'
>   newmask = re.sub('\*', '.*', re.sub('\?', '.', mask))
> result in that:
>   re.search(newmask, host) == True

For a start, you must mean bool(re.search(newmask, host)) == True, 
because re.search() returns a MatchObject or None; neither of those will 
  ever compare equal to True.

Moving right along, you have only one facet of your multi-faceted 
multi-level problem fixed. Consider the following:

|>>> newmask
'[EMAIL PROTECTED]'
|>>> host = '[EMAIL PROTECTED]'
|>>> bool(re.search(newmask, host))
True
|>>> host2 = '[EMAIL PROTECTED]'
|>>> bool(re.search(newmask, host2))
True
|>>> host3 = '[EMAIL PROTECTED]'
|>>> bool(re.search(newmask, host3))
True

You didn't answer either of my questions that would have told me whether 
host2 is a problem; if it is, you need a '$' at the end of newmask.

To fix the host3 problem, you need '\.' instead of '.'.

There is another possible host2-like problem: if you have a hostmask 
that starts with 'one' (i.e. no '*' at the front), what you are doing 
now will give True for incoming starting with 'anyone!' or 
'I_am_the_one!' or whatever. I don't think you want that to happen. Two 
solutions: (1) Put '^' at the start of newmask (2) use re.match() 
instead of re.search().

Another question: should you be doing a case-insensitive match? If so, 
you need re.search/match(newmask, host, re.IGNORECASE)

You may wish to consider looking at the fnmatch module, at three levels:
(1) calling fnmatch.fnmatchcase() may be good enough for your purpose
(2) you can use the undocumented fnmatch.translate(), like this:
 newmask = fnmatch.translate(mask)
and use re.match()
(3) you can find the source code in
/Lib/fnmatch.py,
copy the translate function, and rip out the lines that treat '[' as 
special.

HTH,
John
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[Christoph Zwerschke]

>> Simon Percivall wrote:
>>> First: It's perfectly simple in Java to create a binary sort that
>>> sorts all arrays that contain objects; so wrong there.
>> My point was that the *same* Java source example, directly converted to 
>> Python would *automatically* accept all kinds of arrays.
> 
> And the same code converted to SML would automatically work on all
> kinds of arrays and SML is statically typed.  It's a language issue,
> not a typing issue.

Ok, here the point was that Java has *explicit* static typing. SML is 
not a procedural language and uses *implicit* static typing. Therefore 
it shares some of the benefits of dynamically typed languages such as 
Python. However, an SML version of the program would probably still have 
the same bug as the Java version, right?

>> No need to make any extra efforts.
>> By the way, how would you do it in Java? With 
>> function overloading? I would not call that perfectly simple.
> 
> Since Java doesn't allow function overloading that clearly can't be
> the way.  J2SE 5.0 allows generic classes and functions that operate
> on generic containers.  There are some gotchas, but it's not drastically
> more complex than the original int-only java code.

Java doesn't allow function overloading? That would be new to me. Or did 
  you just want to nitpick that it should be more properly called 
"method overloading" in Java? And as you already said, there are some 
gotchas and you would have to wrap int and long etc. I still would not 
call that perfectly simple, as it is in Python.

-- Christoph
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[Fredrik Lundh]

Kaz Kylheku wrote:

> The trouble with your point is that Christoph's original posting refers
> to an article, which, in turn, at the bottom, refers to a bug database
> which shows that the very same defect had been found in Sun's Java
> library!

and as he points out at the top, it was the article author himself who 
wrote that library code:

 /.../ let me tell you how I discovered the bug: The version
of binary search that I wrote for the JDK contained the same
bug. It was reported to Sun recently when it broke someone's
program, after lying in wait for nine years or so.



-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[Christoph Zwerschke]

Kaz Kylheku wrote:
 > You can have statically typed languages with inadequate type safety,
 > and you can have dynamically typed languages with inadequate type
 > safety.

But the point in this example was that the Java program ironically had 
the bug *because* Java handles ints in a type-safe way, while Python 
does not.

 >> What's better about the Python version? First, it will operate on
 >> *any* sorted array, no matter which type the values have.
 >
 > Uh huh! With hard-coded < and = operators, how stupid. What if you
 > want to use it on strings?
 > Would that be a case-insensitive lexicographic comparison, or
 > case-insensitive? How do you specify what kind of less-than and equal
 > you want to do?

Where's the problem? The function uses the standard ordering of the 
values you feed to it, i.e. case-insensitive lexicographical order if 
you feed a lis of ordinary tuples of strings. You can also feed objects 
with a different ordering, like case-insensitive.

Anyway, that was completely not the point. The point was that you could 
take that Java program, convert it directly to Python, and have 
automatically eliminated a bug. I did not claim that the resulting 
Python program was automatically a real good and Pythonic one.

 > -1 to indicate not found? Why copy Java braindamage induced by an
 > antiquated form of static typing? The Java version has to do that

So you would call Python's str.find() method braindamaged as well?

But as I said, that was not the point here anyway.

-- Christoph
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python + WinCE + serial port

[pcm]

Fuzzyman wrote:

> 
> pcm wrote:
>> Hi,
>>
>> Has anyone ever worked on a Python-WinCE-based program that involved
>> serial port management ?
>>
> 
> Because of the size of the runtime and the fragility of the GUI
> toolkits, there has been little serious development with PythonCE.
> (Little not none - and it's great to have Python available.)
> 
> There is no built in support for the serial port in PythonCE (AFAIK).
> Your best bet is using ctypes (for which a PythonCE port has been done)
> and the microsoft API.
> 
> Fuzzyman
> http://www.voidspace.org.uk/python/index.shtml
> 
>> Regards,
>> 
>> Philippe




Thanks, does that mean that I need to write an extension to the WinCE API or
is that built-into the Python package ?

Regards,
Philippe



-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Pyrex list/array

[Jim Lewis]

Thanks for your comments.

> You probably didn't expect the Inquisition...

Correct ;-)

> 1. What is your speed requirement and how far short of that are you at  the 
> moment?

~10 times faster.

> 2. Are you sure there is no Python or third-party module that does what you 
> want?

Yes.

> 3. Is your algorithm the best possible?

I think so although of course one can never be certain.

> 4. Is your Python implementation of that algorithm the best possible? Have 
> you exposed it to the critical gaze of the speed-freaks in this  newsgroup?

Thanks for the good suggestion but I want to try pyrex first.

> 5. Does your architecture support psyco? If so, have you tried that and what 
> were the results?

Already using psyco.

> The question might be better asked on the Pyrex mailing list.

I did not find it - where is it?

> Almost any Python code is also valid Pyrex code. For a start, just compile 
> your function with Pyrex and compare the speed.

It's slower.

> What you do next is going to depend very much on what operations you are 
> performing on  the list and the objects it contains.

Simple list of ints. Comparing sections of lists between each other.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Pyrex list/array

[skip]

>> 5. Does your architecture support psyco? If so, have you tried that
>>and what were the results?

Jim> Already using psyco.

Is it substantially faster with psyco than without?  If psyco is performing
its magic on the critical section of code already, you are going to lose
that when switching to Pyrex.

Skip
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Pyrex list/array

[Jim Lewis]

> Is it substantially faster with psyco than without?  If psyco is performing
> its magic on the critical section of code already, you are going to lose
> that when switching to Pyrex.

Yes but from what I read Pyrex can be a lot faster than psyco under the
right circumstances.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Pyrex list/array

[skip]

>> Is it substantially faster with psyco than without?  If psyco is
>> performing its magic on the critical section of code already, you are
>> going to lose that when switching to Pyrex.

Jim> Yes but from what I read Pyrex can be a lot faster than psyco under
Jim> the right circumstances.

I'm sure that's true.  That also means under the wrong circumstances it
might not. ;-)  Can you post the code that's running too slowly?

Also, note that psyco learned some new tricks at the recent NeedForSpeed
sprint. You might want to check out the latest version from Subversion and
give it a whirl.

Skip
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: if not CGI:

[Max]

Bruno Desthuilliers wrote:
> Max a écrit :
(snip)
> 
> RoR is not bad, but really over-hyped. There's no shortage of at least 
> as good solutions in Python. You may want to look at Django, Turbogears, 
> Pylons, web.py etc. for fullstack MVC frameworks.

That's what I thought!

(snip)
> 
> So the problem is not  "are there good solutions", but "which one to 
> choose" !-) The answer of course depends on what you want and what you 
> like, but taking a few days to play with Turbogears, Django and Pylons 
> might be a good idea.

Good stuff. I'm downloading them now.


Thanks.

--Max
-- 
http://mail.python.org/mailman/listinfo/python-list

in python , could I accomplish the purpose that "a=Console.read()" used in C?

[python]

in python , could I accomplish the purpose that "a=Console.read()" used
in C?
when program is running, I wanna add a statement like
"a=Console.read()" in C language,it will wait for user's input, after
user's typing a character , and click "enter" key, the program will go
on running.

-- 
http://mail.python.org/mailman/listinfo/python-list

HOST - dreamhost.com / Liberality (Hosting, Basic Requirement)

[Ilias Lazaridis]

crossposted to 5 groups, which are affected by this case.

followup not applicable.

-

I am currently selecting a Hosting Provider / Project Host...

http://case.lazaridis.com/multi/wiki/Host

For this larger scale project...

http://case.lazaridis.com/multi

-

An incident within usenet has reminded me to include a very Basic
Requirement, which is "Terms of Service / Liberality".

-

The incident:

http://xahlee.org/Periodic_dosage_dir/t2/harassment.html

It _seems_ that Mr. Xah Les's account was terminated by dreamhost.com
because of

a) the inability of several people to detect the interconnections within 
writings which lead to perfectly valid cross-posts within the usenet.

b) the non-liberal and essentially non-professional way of how 
dreamhost.com deals with abuse complaints.

-

The accusations of "dreamhost.com" are simply wrong.

The behaviour of dreamhost.com looks like a case of "selective ruling", 
whilst using a right defined within the "Terms of Service" to terminate 
accounts essentially at free will.

Can someone trust his business or even his private activities to a
hosting company, which cancels accounts in such a way?

I do not:

http://case.lazaridis.com/multi/wiki/DreamhostAudit

But possibly I am wrong, and all this is just a missunderstanding.

-

To dreamhost.com:

You should install an autoresponder to your abuse email, which reminds
people that it is

* nearly inpossible to rate the content posted to usenet
* neally inpossible to detect validity of cross-posts
   especially within complex analytical/philosophical writings
* other important facts

People can then decide if they still wish to send the abuse complain
(e.g. can follow a link within the autoresponder).

You should additionally make a clear statement, that you do _not_ have
the right to cancel acounts _without_ any reason, and that you do _not_
intervene into a persons right to speek within the usenet, without a
clear and undoubtable proof of abuse (e.g. court decision, or at least 
verfication of independend entities or mediators).

Additionally, it would be gentle if your company would make a _public_ 
statement subjecting this case, thus any interested party can verify the 
validity of the statements.

-

To Mr. Xah Lee:

You should change to a more liberal services provider, one which
plays in the "Major League" and which respects free speech. Such a
provider would just reject such ridiculous abuse complaints.

If, for any reason, you are not able to switch to another hosting
provider, please let me know.

I will see what I can do for you to keep your free speech up.

Additionally, I would like to suggest you to not invest too much time 
into all this. Better use this time to find people and to react in an 
organized manner.

-

To the complaining people:

To which 'species' do you belong?

http://lazaridis.com/core/eval/species.html

Setting up an thread filter:

http://lazaridis.com/core/eval/filter.html

I have seldom seen a more ridiculous argumentation-line than then 
"spam/abuse" one.

-

To anyone:

Any form of censorship and "suppression of freedom of expression" should 
be kept out of from open-source projects and from usenet.

It is the within the responsibility of every entity (including 
commercial companies) to act against it.

http://dev.lazaridis.com/base/wiki/LiberalProjectDefinition

-
-
-

.

-- 
http://lazaridis.com

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: ANN: PQRC - Python Quick Reference Card - v 0.55

[Kent Johnson]

Laurent Pointal wrote:
> And I'll maintain a fixed URL at
> 
> http://laurent.pointal.org/python/pqrc/

Broken at the moment.

Kent
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Pyrex list/array

[John Machin]

On 4/06/2006 7:59 PM, Jim Lewis wrote:
> Thanks for your comments.
> 
>> You probably didn't expect the Inquisition...
> 
> Correct ;-)

Nobody does :-)

> 
>> The question might be better asked on the Pyrex mailing list.
> 
> I did not find it - where is it?

Evidently somewhere near the Hall of the Mountain King. A reference to 
it is cunningly concealed in the last place one would think of finding 
it: under the heading "Mailing List" on the Pyrex home page :-) Here: 
http://lists.copyleft.no/mailman/listinfo/pyrex ... get in quick before 
the pirate moves it again.

> 
>> Almost any Python code is also valid Pyrex code. For a start, just compile 
>> your function with Pyrex and compare the speed.
> 
> It's slower.
> 
>> What you do next is going to depend very much on what operations you are 
>> performing on  the list and the objects it contains.
> 
> Simple list of ints. Comparing sections of lists between each other.

Do you mean alist[x:x+n] == alist[y:y+n] ?
If so, that's creating two new lists each of size n, and then comparing 
those two lists. I doubt that psyco would recognize that it didn't need 
to copy the two slices. The first step might be to write functions to 
compare without copying, e.g.:

def py_slices_cmp_eq(py_list, start1, start2, size):
 """Return 1 if py_list[start1+size] == py_list[start2+size]
 else 0"""
 offset = start2 - start1
 for i in xrange(start1, start1+size):
 if py_list[i] != py_list[i+offset]:
 return 0
 return 1

See what psyco makes of that.
Then turn that into a cdef function for Pyrex.

If that's still not fast enough, then you might be in for some harder work:

Allocate memory for a C array, unpack your list into it, write 
comparison functions c_slices_cmp_* that operate on your array of ints.
There should be no Python stuff in there, only C constructs. You can 
even use memcmp() for the cmp_eq function.

Which brings us back to your original question "Do I need to convert to 
array or something so pyrex can generate tight code?" ...
1. Some of the above may help you to determine whether you need to.
2. Without any knowledge of the size of your list or what you are doing, 
we can't help you much more on whether you need to.
3. AFAICT, Pyrex doesn't do much in the way of optimisation, leaving 
that up to the C compiler. Generating tight code would depend more on 
you replacing appropriately-chosen Pythonisms with C-isms.

As for *how* to make your C array, something like this:

cdef extern from "Python.h":
void   PyMem_Free(void *p)
void*  PyMem_Malloc(int n) except NULL
# untested -- compiles OK :-)
cdef int * int_array_from_list(object ilist):
 cdef int n, i
 cdef int * arrayp
 n = len(ilist)
 arrayp = PyMem_Malloc(n * sizeof(int))
 for i from 0 <= i < n:
 arrayp[i] = ilist[i]
 return &arrayp[0]

Hoping some of this helps,
John
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: logging

[Vinay Sajip]

Hello Baurzhan,

> Consider the following scenario: root is CRITICAL, l01 is DEBUG, a debug
> message is logged on l01. l01 decides that the message should be
> printed, and _both_ root and l01 print it. Now, it is good that the
> message is propagated to root, but why doesn't root decide for itself
> whether to print it or not?

It's not propagated to the root logger (or to ancestor loggers in
general) - just to the handlers associated with ancestor loggers.

> For instance, I log root to syslog and have only critical messages
> there. I log l01 to console to debug. I want that my message to l01 is
> not printed by root since its level is CRITICAL. This is why I want that
> each logger re-evaluates the message level for itself. Could you perhaps
> give a useful example why one could want loggers to decide once?

You can set levels on handlers as well as loggers. So if you add a
syslog handler to the root and set its level to CRITICAL, only CRITICAL
messages are sent to syslog.

> And another thing I couldn't find how to do: I want to have several
> debug levels. I can log messages without problems, but numeric values in
> the configuration file cause error messages during
> logging.config.fileConfig. Can I specify numeric values in the config
> file?

You should use addLevelName to add custom levels. You can do e.g.

logging.MYCUSTOMLEVEL  = 25
logging.addLevelName(logging.MYCUSTOMLEVEL, "MYCUSTOMLEVEL")

and then reference MYCUSTOMLEVEL in the config file.

Regards,

Vinay

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[nikie]

Let's look at two different examples: Consider the following C# code:

static decimal test() {
   decimal x = 10001;
   x /= 100;
   x -= 100;
   return x;
}

It returns "0.01", as you would expect it. Now, consider the python
equivalent:

def test():
x = 10001
x /= 100
x -= 100
return x

It returns "0". Clearly an error!
Even if you used "from __future__ import division", it would actually
return "0.015116", which, depending on the context, may
still be an intolerable error.

Morale: the problem isn't whether the the types are chosen at
compile-time or at runtime, it's simply _what_ type is chosen, and
whether it's appropriate or not.

I can even think of an example where C's (and Java's) bounded ints are
the right choice, while Python's arbitraty-precision math isn't: Assume
you get two 32-bit integers containing two time values (or values from
an incremental encoder, or counter values). How do you find out how
many timer ticks (or increments, or counts) have occured between those
two values, and which one was earlier? In C, you can just write:

   long Distance(long t1, long t0) { return t1-t0; }

And all the wraparound cases will be handled correctly (assuming there
have been less than 2^31 timer ticks between these two time values).
"Distance" will return a positive value if t1 was measured after t0, a
negative value otherwise, even if there's been a wraparound in between.
Try the same in Python and tell me which version is simpler!

-- 
http://mail.python.org/mailman/listinfo/python-list

Pyrex newbie question

[Philip Smith]

Just starting to use pyrex on windows.

Using pyrex version 0.9.3.1.win32

Using Activestate Python 2.4.3.12

Using Mingw compiler

When I try to run the pyrex demo it fails with a message:

"undefined reference to '_imp__Py_NoneStruct' "

Anyone know why? 


-- 
http://mail.python.org/mailman/listinfo/python-list

Re: ANN: PQRC - Python Quick Reference Card - v 0.55

[gene tani]

Laurent Pointal wrote:
> [for those who dont read clp.announce]
>
> The Python Quick Reference Card (PQRC) aims to provide a printable quick
> reference documentation for the Python language and some of its main
> standard libraries (currently for Python 2.4).
>
> PQRC tries to group informations about same/similar subject to avoid
> searching in multiple places.
>

very nice.  There's a few others I've collected over the years.  I
havent found an OS X dashboard widget yet tho:

http://rgruet.free.fr/#QuickRef

http://infohost.nmt.edu/tcc/help/pubs/python22.pdf
http://www.onlamp.com/python/excerpt/PythonPocketRef/examples/python.pdf
http://diveintopython.org/appendix/abstracts.html

http://www.yukoncollege.yk.ca/~ttopper/COMP118/rCheatSheet.html
http://www.schacherer.de/frank/tech/tools/python.html

http://www.experimentierkasten.de/python_php.pdf
http://ferg.org/pyref/index.html

http://projects.edgewall.com/python-sidebar/
http://jotsite.com/blogArchives/2006_03.php#000383

http://www.drweb.de/weblog/weblog/?p=571
http://www.petefreitag.com/item/455.cfm

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Pyrex list/array

[Jim Lewis]

> cunningly concealed in the last place one would think of finding it: under 
> the heading "Mailing List" on the Pyrex home page :-)

Hmmm - maybe I should try the scroll bar occassionally ;-)

> Do you mean alist[x:x+n] == alist[y:y+n] ?

OK, probably you an Skip are right - let's see if I missed something at
the Python level.

There are essentially two differences from your snip above. I am trying
to compute n and there are multiple (under 10) lists. Size of lists are
typically under 100 ints.

> ...See what psyco makes of that.

I'm doing a similar straightforward loop approach but it's too slow.

Jim

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: PUDGE - Project Status, Alternative Solutions

[Ilias Lazaridis]

Ilias Lazaridis wrote:
> What is going on with the pudge project?

Any chance to get an comment on this?

> Mr. Patrik O'Brien (Orbtech LLC) had told me that there is no similar 
> tool available within the python domain, thus I have invested some 
> effort to create a Website template, and to enable pudge to generate 
> colored code:
> 
> http://audit.lazaridis.com/schevo/wiki/SchevoWebsiteReview
> 
> I like to reuse the results for personal projects, but I am wondering 
> that the pudge email-list is death (since the server update) - and that 
> no one of the project reacts to personal and public postings.
> 
> Additionally, the schevo project removes the pudge stuff, mscott, the 
> developer which has introduced pudge removes it again (although this was 
> done with several other tools in the past, too):
> 
> http://schevo.org/trac/changeset/2127
> 
> -
> 
> Is there a similar tool available, with which I can generate python 
> documentation / websites or both based on templates and reST?
> 
> Or an overview of such tools?
> 
> I mean such an organized tool is essential for developmente with python.
> 
> .
> 


-- 
http://lazaridis.com
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[D H]

Christoph Zwerschke wrote:
> 
> See the following web page if you dont find it ;-)
> http://googleresearch.blogspot.com/2006/06/extra-extra-read-all-about-it-nearly.html
>  

The point of that is that it did fail.  It threw an 
ArrayIndexOutOfBoundsException exception.  But it was just luck that 
happened.  Unfortunately I don't think java and C# have integer overflow 
checking turned on by default.

Take this longArithmetic benchmark here:
http://www.cowell-shah.com/research/benchmark/code
and a story about it here:
http://www.osnews.com/story.php?news_id=5602&page=3

The java and C# versions are fast (15 seconds for me), BUT, they
give the incorrect result because of an overflow error.
The python version gives the correct result because it transparently
changes the underlying types to handle the larger numbers, BUT this
causes it to run over 20X slower than Java or C#.  It takes 10 minutes
to complete in python, not 15 seconds.  With psyco, it takes 5 minutes.

So to say the story you pointed out shows that python is superior
is a matter of perspective.  Yes, python gave the correct result
by silently changing the underlying types to longs, and that is
what I would expect of a scripting language.  But the price is
speed.  In both these cases, I would rather be made aware of the
error in the code and fix it so I didn't have to suffer slowdowns.

That is why in boo ( http://boo.codehaus.org/ ) luckily overflow 
checking is enabled by default, and it throws a overflow exception at
runtime to tell you something is wrong with your code.  When you
then fix for that, you get the same 15 second time just like java
and C#.
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: HOST - dreamhost.com / Liberality (Hosting, Basic Requirement)

[Joachim Durchholz]

Ilias Lazaridis schrieb:
> crossposted to 5 groups, which are affected by this case.
> 
> followup not applicable.

Actually, in this case, yes.

> It _seems_ that Mr. Xah Les's account was terminated by dreamhost.com
> because of
> 
> a) the inability of several people to detect the interconnections within 
> writings which lead to perfectly valid cross-posts within the usenet.

Actually, his posts are mostly off-topic.

> b) the non-liberal and essentially non-professional way of how 
> dreamhost.com deals with abuse complaints.

Unless you give some concrete facts, this is simply slander.
URLs don't count.

> To dreamhost.com:
> 
> You should install an autoresponder to your abuse email, which reminds
> people that it is
> 
> * nearly inpossible to rate the content posted to usenet
> * neally inpossible to detect validity of cross-posts
>   especially within complex analytical/philosophical writings
> * other important facts

Why are you wasting our mental bandwidth with that?
Besides, it's utter nonsense. There's an infinity of invalid reasons, so 
you can't rule them out with an autoresponder.

> People can then decide if they still wish to send the abuse complain
> (e.g. can follow a link within the autoresponder).

Nope. Finding out the provider is enough of a barrier. Additional 
barriers are not really necessary.
Xah Lee has been irritating people for months.

I do share your concerns. Complaint handling often is unprofessional. 
However, in Xah Lee's case, he's indeed been irritating too many people 
for a too long time that *some* sanction is in fact appropriate.
I routinely kill his threads, but I'm reading a specific newsgroup for a 
purpose, and Xah Lee requires me to kill his. He's essentially doing 
semantic spam - analytical and philosophical writings may be well and 
fine, but they aren't appropriate on the newsgroups that I frequent (or 
only in very specific ways that Xah Lee doesn't address).

> To anyone:
> 
> Any form of censorship and "suppression of freedom of expression" should 
> be kept out of from open-source projects and from usenet.
> 
> It is the within the responsibility of every entity (including 
> commercial companies) to act against it.
> 
> http://dev.lazaridis.com/base/wiki/LiberalProjectDefinition

There are many important goals. Free speech is indeed very high on the 
list. On the other hand, I'm pretty sure that Xah Lee will find another 
provider.
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: linking errors with debug build of Python2.4.3

[Martin Wiechert]

You were right, leaving out --with-pydebug did the trick.

Thanks, Martin


On Sunday 28 May 2006 03:53, [EMAIL PROTECTED] wrote:
> Martin Wiechert wrote:
> > Hi list,
> >
> > I've created a fresh build of Python 2.4.3 using the following
> > configuration
> >
> > $ ./configure --with-pydebug --prefix=/usr/local/debug --enable-shared
> > --with-fpectl --with-signal-module
> >
> > What did I do wrong?
>
> Try with just:  ./configure --with-pydebug --prefix=/usr/local/debug
>
> I think the problem is --enable-shared.  I'm not sure what you are
> doing, but you probably don't need the other options.  The signal
> module should always be built, I've never even seen the
> --with-signal-module option. :-)
>
> n
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: create a text file

[Stan Cook]

Fredrik Lundh wrote:
> Stan Cook wrote:
> 
>> I'm writing a script to list all of my music files' id3 tags to a 
>> comma delimited file.  The only part I'm missing seems like it should 
>> be the simplest.  I haven't used Python for the last couple of years.  
>> My question is this:
>>
>> When I use os.open(,"w"), I get an error 
>> message,TypeError: an integer is required.  Has something 
>> changed?  Did I miss something???
> 
> the function is called "open", not "os.open".
> 
> there's an open function in the os module, but that's doing something 
> slightly different (see the library reference documentation for details 
> if you're curious).
> 
> 
> 
Thanks, I found it.
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: in python , could I accomplish the purpose that "a=Console.read()" used in C?

[Dennis Benzinger]

python wrote:
> in python , could I accomplish the purpose that "a=Console.read()" used
> in C?
> when program is running, I wanna add a statement like
> "a=Console.read()" in C language,it will wait for user's input, after
> user's typing a character , and click "enter" key, the program will go
> on running.
> 


Use raw_input() :

age = raw_input("Your age: ")
print age


Bye,
Dennis
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: carshing the interpreter in two lines

[Mel Wilson]

sam wrote:
> Mel:
> Wow that book brings back memories. I scanned my copy to review the
> subject covered, and came to the conclusion that mind reading
> algorithms are the answer.
> 
I gathered from somewhere (but not the index to Andrew 
Hodges' biography) that Turing was toying with an idea for 
"oracles", where a computation would be allowed to call out 
sometimes to a non-computational process to obtain some 
required result.  Used maybe by  interactive debugging programs.

 Cheers,Mel.

> Mel Wilson wrote:
[ ... ]
>>Douglas Hofstadter's _Goedel, Escher, Bach: an Eternal Golden Braid_.
[ ... ]
>> "Contracrostipunctus".
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: how to print newline in xml?

[uche . ogbuji]

[EMAIL PROTECTED] wrote:
> I use Python/XML packages are xml.dom.minidom and xml.dom.ext (second
> just for PrettyPrint)

You don't need xml.dom.ext for prettyprint.  You can use
doc.toprettyxml()

I gather you want to tweak the prettyprinter to not add the newline
before the comment.  The only way to do this is to write your own
printing logic, which is really not that hard, if you just start by
copying the code from .writexml (used by .toprettyxml).

But there's an even easier (if slower) way: pretty print the document,
then parse it in again, remove the text node between the element in
question and the following comment, and then use .writexml() to
serialize it it again.

A few general notes:

* You cannot set the order of attributes in most XML tools, whether
Python or not.  This is unfortunate for people who would like to
preserve such details for usability reasons, but that's just the way
XML is.  The closest you can get is by using canonicalization [1],
which is available in PyXML as xml.dom.ext.c14n.  It just so happens
that canonical XML leaves the attributes in the order you want.  You
won't always be so lucky.

* You can always create text nodes by using doc.createTextNode.

* You can always remove text nodes (or any other kind) by using
.removeChild

* It's much easier to navigate if you use XPath.  PyXML has an
xml.xpath module you can use.

Good luck.

[1] http://www-128.ibm.com/developerworks/xml/library/x-c14n/

--
Uche Ogbuji   Fourthought, Inc.
http://uche.ogbuji.nethttp://fourthought.com
http://copia.ogbuji.net   http://4Suite.org
Articles: http://uche.ogbuji.net/tech/publications/

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Proposed new PEP: print to expand generators

[Mel Wilson]

Terry Reedy wrote:
> "James J. Besemer" <[EMAIL PROTECTED]> wrote in message 
> news:[EMAIL PROTECTED]
>> I propose that we extend the semantics of "print" such that if the object 
>> to
>> be printed is a generator then print would iterate over the resulting
>> sequence of sub-objects and recursively print each of the items in order.
> Iterating over an iterator is usually destructive.  So you would be 
> printing what it was but no longer is.  This is why iterators are printed 
> differently from sequences.

I guess the motivation is the case of people who would set 
up an iterator specifically to print from it.

print-as-debug-aid would get badly broken by the proposal, 
and I'd find that painful.

 Mel.
-- 
http://mail.python.org/mailman/listinfo/python-list

mutable member, bug or ...

[Sambo]

By accident I assigned int to a class member 'count' which was initialized to 
(empty) string and had no error till I tried to use it as string, obviously. 
Why was there no error on assignment( near the end ). 


class Cgroup_info:
group_name = ""
count = "0"  #last time checked and processed/retrieved
first = "0"
last = ""
retrieval_type = ""# allways , ask( if more than some limit), none
date_checked = ""
time_checked = ""
new_count = ""
new_first = ""
new_last = ""
# local storage maintanance vars
pointer_file = ""
message_file = ""
#maintanance vars
cur_mess_num = 0
cur_mess_id = ""

def __init__( self ):
group_name = ""
count = "0"  #last time checked and processed/retrieved

def get_count( self ):
print self.count, type( self.count )
return string.atoi( self.count, 10 )

class server_info:
def "(server_info::)"get_group_stat( self, grp ):

gr_info = Cgroup_info()
gr_info.group_name = grp
try:
ind = self.group_list.index( grp )
except ValueError:
gr_info.count(0)
return ( gr_info )
print ind
if len( self.group_list[ind].split() ) == 4:
gr_info.count = self.group_list[ind].split()[1]
gr_info.first = self.group_list[ind].split()[2]
gr_info.last = self.group_list[ind].split()[3]
else:
gr_info.count = gr_info.first = gr_info.last = "0"
return( gr_info )
-- 
http://mail.python.org/mailman/listinfo/python-list

Installation Problem

[Marshall Dudley]

I am trying to install python, but am having problems.  I did what the
README file said, and it created an executible code in the current
directory as it said it would when I typed "make". It seemed to say to
copy the executable over to the /usr/local directory, which I did.

If I type ./python in the directory I did the make in I get:

execonn# ./python
Python 2.4.3 (#1, May 31 2006, 07:50:04)
[GCC 2.95.4 20020320 [FreeBSD]] on freebsd4
Type "help", "copyright", "credits" or "license" for more information.
>>>

Which is I believe correct.

But if I type /usr/local/python I get:

Python 2.4.3 (#1, May 31 2006, 07:50:04)
[GCC 2.95.4 20020320 [FreeBSD]] on freebsd4
Type "help", "copyright", "credits" or "license" for more information.
>>>
execonn# /usr/local/python
Could not find platform independent libraries 
Could not find platform dependent libraries 
Consider setting $PYTHONHOME to [:]
'import site' failed; use -v for traceback
Python 2.4.3 (#1, May 31 2006, 07:50:04)
[GCC 2.95.4 20020320 [FreeBSD]] on freebsd4
Type "help", "copyright", "credits" or "license" for more information.
>>>

So nothing that tries to use it works.

Any assistance would be appreciated.

Thanks,

Marshall

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: ideas for programs?

[Florian Diesch]

Brandon McGinty <[EMAIL PROTECTED]> wrote:


> I've been learning python for the past couple of months and writing
> misc scripts here and there, along with some web apps.
> I'm wondering if anyone has ideas of programs I might try my hand at making?

Something I wanted a few days ago: I have a graph described in the .dot
language (used by GraphViz ) and want you get
things like "shortest path between two nodes", "all paths between two
nodes", "all cycles" and whatever graph theory knows as interesting. 


   Florian
-- 

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Installation Problem

[Fredrik Lundh]

Marshall Dudley wrote:
> I am trying to install python, but am having problems.  I did what the
> README file said, and it created an executible code in the current
> directory as it said it would when I typed "make".

"make" doesn't install the interpreter by itself; you're supposed to use 
"make install" (or "make altinstall") to do that.

just copying the interpreter binary around won't give you a complete 
install.

 > It seemed to say to copy the executable over to the /usr/local
 > directory, which I did.

the README says:

   To start building right away (on UNIX): type "./configure" in the
   current directory and when it finishes, type "make".  This creates an
   executable "./python"; to install in /usr/local, first do "su root"
   and then "make install".

the detailed installation section says:

   To install the Python binary, library modules, shared library modules
   (see below), include files, configuration files, and the manual page,
   just type

 make install

/.../



-- 
http://mail.python.org/mailman/listinfo/python-list

Re: mutable member, bug or ...

[Fredrik Lundh]

Sambo wrote:

> By accident I assigned int to a class member 'count' which was
 > initialized to (empty) string and had no error till I tried to
 > use it as string, obviously. Why was there no error on assignment
 > (near the end ).

Python uses dynamic typing, which means that objects have types, but 
variables don't.  A variable is just a name.

I suggest reading up on variables, namespaces and classes/instances in 
your favourite tutorial.  Python's not C++, and you won't get very far 
by pretending that it is.



-- 
http://mail.python.org/mailman/listinfo/python-list

Re: deleting texts between patterns

[Baoqiu Cui]

John Machin <[EMAIL PROTECTED]> writes:

> Uh-oh.
>
> Try this:
>
 pat = re.compile('(?<=abc\n).*?(?=xyz\n)', re.DOTALL)
 re.sub(pat, '', linestr)
> 'blahfubarabc\nxyz\nxyzzy'

This regexp still has a problem.  It may remove the lines between two
lines like 'aaabc' and 'xxxyz' (and also removes the first two 'x's in
'xxxyz').

The following regexp works better:

  pattern = re.compile('(?<=^abc\n).*?(?=^xyz\n)', re.DOTALL | re.MULTILINE)

>>> lines = '''line1
... abc
... line2
... xyz
... line3
... aaabc
... line4
... xxxyz
... line5'''
>>> pattern = re.compile('(?<=^abc\n).*?(?=^xyz\n)', re.DOTALL | re.MULTILINE)
>>> print pattern.sub('', lines)
line1
abc
xyz
line3
aaabc
line4
xxxyz
line5
>>> 

- Baoqiu

-- 
Baoqiu Cui 
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: carshing the interpreter in two lines

[Aahz]

In article <[EMAIL PROTECTED]>,
gangesmaster <[EMAIL PROTECTED]> wrote:
>
>the following (random) code crashes my interpreter
>(python 2.4.3/winxp):
>
>from types import CodeType as code
>exec code(0, 5, 8, 0, "hello moshe", (), (), (), "", "", 0, "")
>
>i would expect the interpreter to do some verifying, at least for
>sanity (valid opcodes, correct stack size, etc.) before executing
>artbitrary code... after all, it was the BDFL who said """I'm not
>saying it's uncrashable. I'm saying that if you crash it, it's a
>bug unless proven harebrained."""

IIRC, this has been discussed before and deemed harebrained.  Check SF to
see whether this specific case has been submitted previously and submit
it if not.  Then post to python-dev if it's a new bug and ask for a
ruling on whether it's harebrained.
-- 
Aahz ([EMAIL PROTECTED])   <*> http://www.pythoncraft.com/

"I saw `cout' being shifted "Hello world" times to the left and stopped
right there."  --Steve Gonedes
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Installation Problem

[Marshall Dudley]

Sorry, this is a FreeBSD system 4.8-RELEASE

I found another set of documents that say to use the following to
install::

python setup.py install

but after running it, I still have the same problem.

Marshall

Marshall Dudley wrote:

> I am trying to install python, but am having problems.  I did what the
> README file said, and it created an executible code in the current
> directory as it said it would when I typed "make". It seemed to say to
> copy the executable over to the /usr/local directory, which I did.
>
> If I type ./python in the directory I did the make in I get:
>
> execonn# ./python
> Python 2.4.3 (#1, May 31 2006, 07:50:04)
> [GCC 2.95.4 20020320 [FreeBSD]] on freebsd4
> Type "help", "copyright", "credits" or "license" for more information.
> >>>
>
> Which is I believe correct.
>
> But if I type /usr/local/python I get:
>
> Python 2.4.3 (#1, May 31 2006, 07:50:04)
> [GCC 2.95.4 20020320 [FreeBSD]] on freebsd4
> Type "help", "copyright", "credits" or "license" for more information.
> >>>
> execonn# /usr/local/python
> Could not find platform independent libraries 
> Could not find platform dependent libraries 
> Consider setting $PYTHONHOME to [:]
> 'import site' failed; use -v for traceback
> Python 2.4.3 (#1, May 31 2006, 07:50:04)
> [GCC 2.95.4 20020320 [FreeBSD]] on freebsd4
> Type "help", "copyright", "credits" or "license" for more information.
> >>>
>
> So nothing that tries to use it works.
>
> Any assistance would be appreciated.
>
> Thanks,
>
> Marshall

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Installation Problem

[Marshall Dudley]

Fredrik Lundh wrote:

> Marshall Dudley wrote:
> > I am trying to install python, but am having problems.  I did what the
> > README file said, and it created an executible code in the current
> > directory as it said it would when I typed "make".
>
> "make" doesn't install the interpreter by itself; you're supposed to use
> "make install" (or "make altinstall") to do that.
>
> just copying the interpreter binary around won't give you a complete
> install.
>
>  > It seemed to say to copy the executable over to the /usr/local
>  > directory, which I did.
>
> the README says:
>
>To start building right away (on UNIX): type "./configure" in the
>current directory and when it finishes, type "make".  This creates an
>executable "./python"; to install in /usr/local, first do "su root"
>and then "make install".

Yes, that is what I did. Since I ended up with no executable in /usr/local,
or /usr/local/bin and it said " This creates an
   executable "./python" (which it did); to install in /usr/local" I copied
the one it created over to /usr/local, then later /usr/local/bin

>
>
> the detailed installation section says:
>
>To install the Python binary, library modules, shared library modules
>(see below), include files, configuration files, and the manual page,
>just type
>
>  make install
>
> /.../
>
> 

Yes, I typed "make install".  But nothing gets put into /usr/local or
/usr/local/bin without me copying it over.  And if I run python it in the
directory I unpacked it in, it works, but if I run the copy in /usr/local or
/usr/local/bin it does not.

I also tried the instuctions on their web site:

"python setup.py install"

But get the same result, but it copies and puts the following 3 files in the
/usr/local/bin dir.

-rwxr-xr-x  1 root  wheel   96 May 31 07:50 idle
-rwxr-xr-x  1 root  wheel   81 May 31 07:50 pydoc
-rwxr-xr-x  1 root  wheel18017 May 31 07:50 smtpd.py

Marshall

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: grouping a flat list of number by range

[joh12005]

Hello

> ... _, first_n = group[0]

what is the meaning of the underscore "_" ? is it a special var ? or
should it be readed as a way of unpacking a tuple in a non useful var ?
like 

lost, first_n = group[0]

best regards.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Installation Problem

[Warren Block]

Marshall Dudley <[EMAIL PROTECTED]> wrote:
> Sorry, this is a FreeBSD system 4.8-RELEASE
>
> I found another set of documents that say to use the following to
> install::
>
> python setup.py install
>
> but after running it, I still have the same problem.

[top-posting trimmed, please don't do that]

Doesn't the port work for 4.8?  It does work on FreeBSD 4.11, but there 
may have been changes to the ports system since 4.8.  (You should 
consider updating to 4.11.)

There are several patch files in the FreeBSD port, including
one to setup.py.

The easiest way is to cvsup your ports tree and then

cd /usr/ports/lang/python
make
make install
make clean

-- 
Warren Block * Rapid City, South Dakota * USA
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: grouping a flat list of number by range

[K.S.Sreeram]

Yup! '_' is just used as a dummy. Its a pretty common idiom. There's
nothing special about that variable.

[EMAIL PROTECTED] wrote:
> Hello
> 
>> ... _, first_n = group[0]
> 
> what is the meaning of the underscore "_" ? is it a special var ? or
> should it be readed as a way of unpacking a tuple in a non useful var ?
> like 
> 
> lost, first_n = group[0]
> 
> best regards.
> 




signature.asc
Description: OpenPGP digital signature
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: grouping a flat list of number by range

[Steven Bethard]

[EMAIL PROTECTED] wrote:
>> ... _, first_n = group[0]
> 
> what is the meaning of the underscore "_" ? is it a special var ? or
> should it be readed as a way of unpacking a tuple in a non useful var ?
> like 
> 
> lost, first_n = group[0]

Yep, it's just another name.  "lost" would have worked just as well. 
It's pretty typical around here to see "_" used when a tuple is unpacked 
but some of the values aren't used.  So if you see something like::

 for _, dirs, _ in os.walk(top):
 ...

it just means that the "..." code is only going to use "dirs" (not the 
root path or files that are also available from the os.walk() iterator).

STeVe
-- 
http://mail.python.org/mailman/listinfo/python-list

Python netstring module

[Will McGugan]

Hi folks,

I have just posted a python 'netstring' module on my blog. Comments welcome!

http://www.willmcgugan.com/2006/06/04/python-netstring-module/

Regards,

Will McGugan
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[Christoph Zwerschke]

nikie wrote:
 > Let's look at two different examples: Consider the following C# code:
 >
 > static decimal test() {
 >decimal x = 10001;
 >x /= 100;
 >x -= 100;
 >return x;
 >
 > It returns "0.01", as you would expect it.

Yes, I would expect that because I have defined x as decimal, not int.

 > Now, consider the python equivalent:
 >
 > def test():
 > x = 10001
 > x /= 100
 > x -= 100
 > return x

No, that's not the Python equivalent. The equivalent of the line

decimal x = 10001

in Python would be

x = 10001.0

or even:

from decimal import Decimal
x = Decimal(10001)

Setting x = 10001 would be equivalent to the C# code

int x = 10001

 > It returns "0". Clearly an error!

That's not clearly an error. If you set int x = 10001 in C#, then you 
also get a "0". By setting x to be an integer, you are implicitely 
telling Python that you are not interested in fractions, and Python does 
what you want. Granted, this is arguable and will be changed in the 
__future__, but I would not call that an error.

By the way, the equivalent Python code to your C# program gives on my 
machine the very same result:
 >>> x = 10001.0; x /= 100; x -= 100; print x
0.01

 > Even if you used "from __future__ import division", it would actually
 > return "0.015116", which, depending on the context, may
 > still be an intolerable error.

With from __future__ import division, I also get 0.01 printed. Anyway, 
if there are small discrepancies then these have nothing to do with 
Python but rather with the underlying floating-point hardware and C 
library, the way how you print the value and the fact that 0.01 can 
principally not be stored exactly as a float (nor as a C# decimal), only 
as a Python Decimal.

 > I can even think of an example where C's (and Java's) bounded ints are
 > the right choice, while Python's arbitraty-precision math isn't:
 > Assume you get two 32-bit integers containing two time values (or
 > values from an incremental encoder, or counter values). How do you
 > find out how many timer ticks (or increments, or counts) have occured
 > between those two values, and which one was earlier? In C, you can
 > just write:
 >
 >long Distance(long t1, long t0) { return t1-t0; }
 >
 > And all the wraparound cases will be handled correctly (assuming there
 > have been less than 2^31 timer ticks between these two time values).
 > "Distance" will return a positive value if t1 was measured after t0, a
 > negative value otherwise, even if there's been a wraparound in
 > between. Try the same in Python and tell me which version is simpler!

First of all, the whole problem only arises because you are using a 
statically typed counter ;-) And it only is easy in C when your counter 
has 32 bits. But what about a 24 bit counter?

Anyway, in Python, you would first define:

def wrap(x, at=1<<31):
 if x < -at:
 x += at*2
 elif x >= at:
 x -= at*2
 return x

Then, the Python program would be as simple:

Distance = lambda t1,t0: wrap(t1-t0)

-- Christoph
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: ANN: PQRC - Python Quick Reference Card - v 0.55

[Laurent Pointal]

Kent Johnson wrote:

> Laurent Pointal wrote:
>> And I'll maintain a fixed URL at
>> 
>> http://laurent.pointal.org/python/pqrc/
> 
> Broken at the moment.

Its back.

Its at my home ADSL, normally online, but my provider reset the connexion
each 24h and its home maintained... the page contains only a link to the
other URL which has the data and is beyond a larger bandwidth server.

A+

Laurent.

> 
> Kent

-- 
http://mail.python.org/mailman/listinfo/python-list

re beginner

[SuperHik]

hi all,

I'm trying to understand regex for the first time, and it would be very 
helpful to get an example. I have an old(er) script with the following 
task - takes a string I copy-pasted and wich always has the same format:

 >>> print stuff
Yellow hat  2   Blue shirt  1
White socks 4   Green pants 1
Blue bag4   Nice perfume3
Wrist watch 7   Mobile phone4
Wireless cord!  2   Building tools  3
One for the money   7   Two for the show4

 >>> stuff
'Yellow hat\t2\tBlue shirt\t1\nWhite socks\t4\tGreen pants\t1\nBlue 
bag\t4\tNice perfume\t3\nWrist watch\t7\tMobile phone\t4\nWireless 
cord!\t2\tBuilding tools\t3\nOne for the money\t7\tTwo for the show\t4'

I want to put items from stuff into a dict like this:
 >>> print mydict
{'Wireless cord!': 2, 'Green pants': 1, 'Blue shirt': 1, 'White socks': 
4, 'Mobile phone': 4, 'Two for the show': 4, 'One for the money': 7, 
'Blue bag': 4, 'Wrist watch': 7, 'Nice perfume': 3, 'Yellow hat': 2, 
'Building tools': 3}

Here's how I did it:
 >>> def putindict(items):
... items = items.replace('\n', '\t')
... items = items.split('\t')
... d = {}
... for x in xrange( len(items) ):
... if not items[x].isdigit(): d[items[x]] = int(items[x+1])
... return d
 >>>
 >>> mydict = putindict(stuff)


I was wondering is there a better way to do it using re module?
perheps even avoiding this for loop?

thanks!
-- 
http://mail.python.org/mailman/listinfo/python-list

how not to run out of memory in cursor.execute

[[EMAIL PROTECTED]]

I am using cx_Oracle and MySQLdb to pull a lot of data from some tables
and I find that the cursor.execute method uses a lot of memory that
never gets garbage collected. Using fetchmany instead of fetchall does
not seem to make any difference, since it's the execute that uses
memory. Breaking the query down to build lots of small tables doesn't
help, since execute doesn't give its memory back, after reading enough
small tables execute returns a memory error. What is the trick to get
memory back from execute in cx_Oracle and MySQLdb?

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Proposed new PEP: print to expand generators

[Terry Reedy]

"Mel Wilson" <[EMAIL PROTECTED]> wrote in message 
news:[EMAIL PROTECTED]
> I guess the motivation is the case of people who would set
> up an iterator specifically to print from it.

for i in gen: print i,
print

is rather trivial and gives one the option to control formatting however.

tjr



-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[nikie]

Christoph Zwerschke wrote:

> nikie wrote:
>  > Let's look at two different examples: Consider the following C# code:
>  >
>  > static decimal test() {
>  >decimal x = 10001;
>  >x /= 100;
>  >x -= 100;
>  >return x;
>  >
>  > It returns "0.01", as you would expect it.
>
> Yes, I would expect that because I have defined x as decimal, not int.
>
>  > Now, consider the python equivalent:
>  >
>  > def test():
>  > x = 10001
>  > x /= 100
>  > x -= 100
>  > return x
>
> No, that's not the Python equivalent. The equivalent of the line
>
> decimal x = 10001
>
> in Python would be
>
> x = 10001.0
>
> or even:
>
> from decimal import Decimal
> x = Decimal(10001)

Hm, then I probably didn't get your original point: I thought your
argument was that a dynamically typed language was "safer" because it
would choose the "right" type (in your example, an arbitrary-pecision
integer) automatically. As you can see from the above sample, it
sometimes picks the "wrong" type, too. Now you tell me that this
doesn't count, because I should have told Python what type to use. But
shouldn't that apply to the Java binary-search example, too? I mean,
you could have told Java to used a 64-bit or arbitrary-length integer
type instead of a 32-bit integer (which would actually be equivalent to
the Python code), so it would do the same thing as the Python binary
search implementation.

> ...
> By the way, the equivalent Python code to your C# program gives on my
> machine the very same result:
>  >>> x = 10001.0; x /= 100; x -= 100; print x
> 0.01

Try entering "x" in the interpreter, and read up about the difference
between str() and repr().

>
>  > Even if you used "from __future__ import division", it would actually
>  > return "0.015116", which, depending on the context, may
>  > still be an intolerable error.
>
> With from __future__ import division, I also get 0.01 printed. Anyway,
> if there are small discrepancies then these have nothing to do with
> Python but rather with the underlying floating-point hardware and C
> library, the way how you print the value and the fact that 0.01 can
> principally not be stored exactly as a float (nor as a C# decimal), only
> as a Python Decimal.

The is OT, but what makes you think a C# decimal can't store 0.01?

>  > I can even think of an example where C's (and Java's) bounded ints are
>  > the right choice, while Python's arbitraty-precision math isn't:
>  > Assume you get two 32-bit integers containing two time values (or
>  > values from an incremental encoder, or counter values). How do you
>  > find out how many timer ticks (or increments, or counts) have occured
>  > between those two values, and which one was earlier? In C, you can
>  > just write:
>  >
>  >long Distance(long t1, long t0) { return t1-t0; }
>  >
>  > And all the wraparound cases will be handled correctly (assuming there
>  > have been less than 2^31 timer ticks between these two time values).
>  > "Distance" will return a positive value if t1 was measured after t0, a
>  > negative value otherwise, even if there's been a wraparound in
>  > between. Try the same in Python and tell me which version is simpler!
>
> First of all, the whole problem only arises because you are using a
> statically typed counter ;-) And it only is easy in C when your counter
> has 32 bits. But what about a 24 bit counter?

Easy, multiply it with 256 and it's a 32-bit counter ;-)
Fortunately, 24-bit-counters are quite rare. 16-bit or 32-bit counters
on the other hand are quite common, especially when you're working
close to the hardware (where C is at home). All I wanted to point out
is that bounded integers do have their advantages, because some people
in this thread apparently have never stumbled over them.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: re beginner

[bearophileHUGS]

SuperHik wrote:
> I was wondering is there a better way to do it using re module?
> perheps even avoiding this for loop?

This is a way to do the same thing without REs:

data = 'Yellow hat\t2\tBlue shirt\t1\nWhite socks\t4\tGreen
pants\t1\nBlue bag\t4\tNice perfume\t3\nWrist watch\t7\tMobile
phone\t4\nWireless cord!\t2\tBuilding tools\t3\nOne for the
money\t7\tTwo for the show\t4'

data2 = data.replace("\n","\t").split("\t")
result1 = dict( zip(data2[::2], map(int, data2[1::2])) )

O if you want to be light:

from itertools import imap, izip, islice
data2 = data.replace("\n","\t").split("\t")
strings = islice(data2, 0, len(data), 2)
numbers = islice(data2, 1, len(data), 2)
result2 = dict( izip(strings, imap(int, numbers)) )

Bye,
bearophile

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: re beginner

[faulkner]

you could write a function which takes a match object and modifies d,
pass the function to re.sub, and ignore what re.sub returns.

# untested code
d = {}
def record(match):
s = match.string[match.start() : match.end()]
i = s.index('\t')
print s, i# debugging
d[s[:i]] = int(s[i+1:])
return ''
re.sub('\w+\t\d+\t', record, stuff)
# end code

it may be a bit faster, but it's very roundabout and difficult to
debug.

SuperHik wrote:
> hi all,
>
> I'm trying to understand regex for the first time, and it would be very
> helpful to get an example. I have an old(er) script with the following
> task - takes a string I copy-pasted and wich always has the same format:
>
>  >>> print stuff
> Yellow hat2   Blue shirt  1
> White socks   4   Green pants 1
> Blue bag  4   Nice perfume3
> Wrist watch   7   Mobile phone4
> Wireless cord!2   Building tools  3
> One for the money 7   Two for the show4
>
>  >>> stuff
> 'Yellow hat\t2\tBlue shirt\t1\nWhite socks\t4\tGreen pants\t1\nBlue
> bag\t4\tNice perfume\t3\nWrist watch\t7\tMobile phone\t4\nWireless
> cord!\t2\tBuilding tools\t3\nOne for the money\t7\tTwo for the show\t4'
>
> I want to put items from stuff into a dict like this:
>  >>> print mydict
> {'Wireless cord!': 2, 'Green pants': 1, 'Blue shirt': 1, 'White socks':
> 4, 'Mobile phone': 4, 'Two for the show': 4, 'One for the money': 7,
> 'Blue bag': 4, 'Wrist watch': 7, 'Nice perfume': 3, 'Yellow hat': 2,
> 'Building tools': 3}
>
> Here's how I did it:
>  >>> def putindict(items):
> ...   items = items.replace('\n', '\t')
> ...   items = items.split('\t')
> ...   d = {}
> ...   for x in xrange( len(items) ):
> ...   if not items[x].isdigit(): d[items[x]] = int(items[x+1])
> ...   return d
>  >>>
>  >>> mydict = putindict(stuff)
>
>
> I was wondering is there a better way to do it using re module?
> perheps even avoiding this for loop?
> 
> thanks!

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: re beginner

[bearophileHUGS]

> strings = islice(data2, 0, len(data), 2)
> numbers = islice(data2, 1, len(data), 2)

This probably has to be:

strings = islice(data2, 0, len(data2), 2)
numbers = islice(data2, 1, len(data2), 2)

Sorry,
bearophile

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[Alan Morgan]

In article <[EMAIL PROTECTED]>,
Christoph Zwerschke  <[EMAIL PROTECTED]> wrote:
>>> Simon Percivall wrote:
 First: It's perfectly simple in Java to create a binary sort that
 sorts all arrays that contain objects; so wrong there.
>>> My point was that the *same* Java source example, directly converted to 
>>> Python would *automatically* accept all kinds of arrays.
>> 
>> And the same code converted to SML would automatically work on all
>> kinds of arrays and SML is statically typed.  It's a language issue,
>> not a typing issue.
>
>Ok, here the point was that Java has *explicit* static typing. SML is 
>not a procedural language and uses *implicit* static typing. Therefore 
>it shares some of the benefits of dynamically typed languages such as 
>Python. However, an SML version of the program would probably still have 
>the same bug as the Java version, right?
>
>>> No need to make any extra efforts.
>>> By the way, how would you do it in Java? With 
>>> function overloading? I would not call that perfectly simple.
>> 
>> Since Java doesn't allow function overloading that clearly can't be
>> the way.  J2SE 5.0 allows generic classes and functions that operate
>> on generic containers.  There are some gotchas, but it's not drastically
>> more complex than the original int-only java code.
>
>Java doesn't allow function overloading?

Brain fart.  You said "function" and I read "operator".

Alan
-- 
Defendit numerus
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[Christoph Zwerschke]

nikie wrote:
 > Hm, then I probably didn't get your original point: I thought your
 > argument was that a dynamically typed language was "safer" because it
 > would choose the "right" type (in your example, an arbitrary-pecision
 > integer) automatically.

No, my point was not to make a general statement. It just stumbled over 
that example and said to myself "that wouldn't have happend with 
Python." And I thought it might be interesting for people on c.l.p as 
well. That was all.

 > As you can see from the above sample, it
 > sometimes picks the "wrong" type, too. Now you tell me that this
 > doesn't count, because I should have told Python what type to use.

Yes. Python did not "pick" that type - you explicitely said that x 
should an int by setting x = 10001.

 > I mean, you could have told Java to used a 64-bit or arbitrary-length
 > integer type instead of a 32-bit integer (which would actually be
 > equivalent to the Python code), so it would do the same thing
 > as the Python binary search implementation.

Right, but then Java would do all index operations in that type, even 
for very small arrays when it's not necessary. That's why people 
probably don't do it.

 > The is OT, but what makes you think a C# decimal can't store 0.01?

A C# data type summary gave me the impression that it was just a more 
accurate but still binary floating point type. But you're right, the 
name "decimal" should have given me a clue that it uses base 10 ;-)

So sorry for the confusion. Forget what I wrote about float. I should 
have corretly written that the equivalent to the C# statement

decimal x = 10001;

is the following Python statement

x = Decimal(10001)

If you do the equivalent thing, Python will give the same result as C#.

 > All I wanted to point out is that bounded integers do have their
 > advantages, because some people in this thread apparently have
 > never stumbled over them.

Sure, I did not want to deny that. The main advantages are speed, and 
dealing with hardware related issues. Your Distance function in C is of 
course much faster than my Python implementation. Surely I wouldn't want 
to write a device driver in Python.

-- Christoph
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: re beginner

[Bruno Desthuilliers]

SuperHik a écrit :
> hi all,
> 
> I'm trying to understand regex for the first time, and it would be very 
> helpful to get an example. I have an old(er) script with the following 
> task - takes a string I copy-pasted and wich always has the same format:
> 
>  >>> print stuff
> Yellow hat2Blue shirt1
> White socks4Green pants1
> Blue bag4Nice perfume3
> Wrist watch7Mobile phone4
> Wireless cord!2Building tools3
> One for the money7Two for the show4
> 
>  >>> stuff
> 'Yellow hat\t2\tBlue shirt\t1\nWhite socks\t4\tGreen pants\t1\nBlue 
> bag\t4\tNice perfume\t3\nWrist watch\t7\tMobile phone\t4\nWireless 
> cord!\t2\tBuilding tools\t3\nOne for the money\t7\tTwo for the show\t4'
> 
> I want to put items from stuff into a dict like this:
>  >>> print mydict
> {'Wireless cord!': 2, 'Green pants': 1, 'Blue shirt': 1, 'White socks': 
> 4, 'Mobile phone': 4, 'Two for the show': 4, 'One for the money': 7, 
> 'Blue bag': 4, 'Wrist watch': 7, 'Nice perfume': 3, 'Yellow hat': 2, 
> 'Building tools': 3}
> 
> Here's how I did it:
>  >>> def putindict(items):
> ... items = items.replace('\n', '\t')
> ... items = items.split('\t')
> ... d = {}
> ... for x in xrange( len(items) ):
> ... if not items[x].isdigit(): d[items[x]] = int(items[x+1])
> ... return d
>  >>>
>  >>> mydict = putindict(stuff)
> 
> 
> I was wondering is there a better way to do it using re module?
> perheps even avoiding this for loop?

There are better ways. One of them avoids the for loop, and even the re 
module:

def to_dict(items):
 items = items.replace('\t', '\n').split('\n')
 return dict(zip(items[::2], map(int, items[1::2])))

HTH
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: re beginner

[Bruno Desthuilliers]

[EMAIL PROTECTED] a écrit :
>>strings = islice(data2, 0, len(data), 2)
>>numbers = islice(data2, 1, len(data), 2)
> 
> 
> This probably has to be:
> 
> strings = islice(data2, 0, len(data2), 2)
> numbers = islice(data2, 1, len(data2), 2)

try with islice(data2, 0, None, 2)
-- 
http://mail.python.org/mailman/listinfo/python-list

Max function question: How do I return the index of the maximum value of a list?

[jj_frap]

I'm new to programming in Python and am currently writing a three-card
poker simulator. I have completed the entire simulator other than
determining who has the best hand (which will be far more difficult
than the aspects I've codes thus far)...I store each player's hand in a
list of hand objects and I determine hand strength via a handstrength
list with one element for each player.

When I try to print the "winner" (I've not coded for kicker strength
and ties yet) via the max function, it returns the maximum value in the
list rather than the index associated with that value.

How do I return the index?

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: ideas for programs?

[Daniel Nogradi]

> I've been learning python for the past couple of months and writing
> misc scripts here and there, along with some web apps.
> I'm wondering if anyone has ideas of programs I might try my hand at
> making?

You could put together a handy CSS generator library that could be
used from a python webapp to generate CSS stylesheets on the fly. I'm
sure many webdevelopers would find this helpful.
-- 
http://mail.python.org/mailman/listinfo/python-list

Where is the ucs-32 codec?

[beni . cherniavsky]

Python seems to be missing a UCS-32 codec, even in wide builds (not
that it the build should matter).
Is there some deep reason or should I just contribute a patch?

If it's just a bug, should I call the codec 'ucs-32' or 'utf-32'?  Or
both (aliased)?
There should be  '-le' and '-be' variats, I suppose.  Should there be a
variant without explicit endianity, using a BOM to decide (like
'utf-16')?
And it should combine surrogates into valid characters (on all builds),
like the 'utf-8' codec does, right?

--
Beni Cherniavsky <[EMAIL PROTECTED]>, who can only read email on
weekends.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Max function question: How do I return the index of the maximum value of a list?

[Sybren Stuvel]

jj_frap enlightened us with:
> When I try to print the "winner" (I've not coded for kicker strength
> and ties yet) via the max function, it returns the maximum value in
> the list rather than the index associated with that value.
>
> How do I return the index?

You can't even be sure it exists - there might be multiple maximum
values. What would you expect in such a case?

Sybren
-- 
The problem with the world is stupidity. Not saying there should be a
capital punishment for stupidity, but why don't we just take the
safety labels off of everything and let the problem solve itself? 
 Frank Zappa
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Max function question: How do I return the index of the maximum value of a list?

[gene tani]

jj_frap wrote:
> I'm new to programming in Python and am currently writing a three-card
> poker simulator. I have completed the entire simulator other than
> determining who has the best hand (which will be far more difficult
> than the aspects I've codes thus far)...I store each player's hand in a
> list of hand objects and I determine hand strength via a handstrength
> list with one element for each player.
>
> When I try to print the "winner" (I've not coded for kicker strength
> and ties yet) via the max function, it returns the maximum value in the
> list rather than the index associated with that value.
>
> How do I return the index?

http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/306862
http://www.rubyquiz.com/quiz24.html

-- 
http://mail.python.org/mailman/listinfo/python-list

RE: C# equivalent to range()

[Delaney, Timothy (Tim)]

Luis M. González wrote:

> There are thousands of threads to choose from in this forum.
> If they didn't like this question, they could have picked any other
> one to discuss.
> There's no need to be disagreeable :-)

Well, there are reasons to reply to a message stating that it's not on-topic 
for the group. The most common reaction to receiving no replies is to start a 
new thread petulantly asking why there were no answers to the original thread. 
If that one gets no replies the most common reaction is start another new 
thread stating that Python sucks, the newsgroup sucks, etc.

Not saying that this is what would have happened in this case, but it is the 
most common sequence of events. Better to head it off before it happens. At 
least any upset replies tend to be restricted to the one thread ;)

Unfortunately, posting a good response, whilst apparently helpful, tends to 
encourage further off-topic postings :(

Tim Delaney
-- 
http://mail.python.org/mailman/listinfo/python-list

RE: Which exceptions are recommended to me handled?

[Delaney, Timothy (Tim)]

Florencio Cano wrote:

> Hello,
> Is it recommended as a good programming practice to catch all
> exceptions and raise our own exceptions or let Python itself raise
> these kinds of exceptions?  
> For example imagine a function that needs an integer and '34' is
> passed, this is ok because inside the function it uses int(variable)
> but if a 'hello' is passed it will raise a ValueError exception. Is
> it better to handle this exception or let Python raise directly
> ValueError and stop execution or what is recommended?   

If you can validly handle the exception, do so. Otherwise, let it
propagate. Valid handling could be (for example) logging the error and
using a default value.

Note that it's a particularly bad idea to just replace one exception
with another exception (not suggesting that that is what you intended -
just something I've seen a lot ;)

try:
int(val)
except ValueError:
raise MyValueError('Bad value: ' + val)

The most important problem here is that you've lost the stack trace from
the original exception. The next most important is that anything else
that believes it can handle a ValueError now won't be able to.

Tim Delaney
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Max function question: How do I return the index of the maximum value of a list?

[Erik Max Francis]

gene tani wrote:

> http://www.rubyquiz.com/quiz24.html

His question was for three-card poker, not normal poker.  The ranking of 
hands in three-card poker isn't the same as in normal best five-card 
poker rankings; for instance, in three-card poker, a straight beats a flush.

-- 
Erik Max Francis && [EMAIL PROTECTED] && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis
   Could it be / That we need loving to survive
   -- Neneh Cherry
-- 
http://mail.python.org/mailman/listinfo/python-list

[ANN] ConfigObj 4.3.2 Released

[Fuzzyman]

`ConfigObj 4.3.2 `_
has just been released.

You can download it from `configobj-4.3.2.zip
`_.

This is a bugfix and minor feature enhancement release. There is a
bugfix in `unrepr mode
`_, and
exception handling has been improved.

The full changelog is :

Changed error handling, if parsing finds a single error then that
error will be re-raised. That error will still have an ``errors`` and a
``config`` attribute. That means the error will be more comprehensible.

Fixed bug where '\n' terminated files could be truncated.

Bugfix in ``unrepr`` mode, it couldn't handle '#' in values.
(Thanks to Philippe Normand for the report.)

As a consequence of this fix, ConfigObj doesn't now keep inline
comments in ``unrepr`` mode. This is because the parser in the
`compiler package `_ doesn't
keep comments. {sm;:-)}

Error messages are now more useful. They tell you the number of
parsing errors and the line number of the first error. (In the case of
multiple errors.)

Line numbers in exceptions now start at 1, not 0.

Errors in ``unrepr`` mode are now handled the same way as in the
normal mode. The errors stored will be an ``UnreprError``.

There is also a proposal to support `PEP 292
`_ string substitution (which
is much better). This will be the target of the next release of
**ConfigObj**.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Where is the ucs-32 codec?

[Erik Max Francis]

[EMAIL PROTECTED] wrote:

> Python seems to be missing a UCS-32 codec, even in wide builds (not
> that it the build should matter).
> Is there some deep reason or should I just contribute a patch?
> 
> If it's just a bug, should I call the codec 'ucs-32' or 'utf-32'?  Or
> both (aliased)?
> There should be  '-le' and '-be' variats, I suppose.  Should there be a
> variant without explicit endianity, using a BOM to decide (like
> 'utf-16')?
> And it should combine surrogates into valid characters (on all builds),
> like the 'utf-8' codec does, right?

Note that UTF-32 is UCS-4.  UCS-32 ("Universial Character Set in 32 
octets") wouldn't make much sense.

Not that Python has a UCS-4 encoding available either.  I'm really not 
sure why.

-- 
Erik Max Francis && [EMAIL PROTECTED] && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis
   Could it be / That we need loving to survive
   -- Neneh Cherry
-- 
http://mail.python.org/mailman/listinfo/python-list

[ANN] ConfigObj 4.3.2 Released

[Fuzzyman]

`ConfigObj 4.3.2 `_
has just been released.

You can download it from `configobj-4.3.2.zip
`_.

ConfigObj is a config file reader and writer. It has *many* features,
but the main one is that it is simple to use. Its features include :

* Nested sections (subsections), to any level
* List values
* Multiple line values
* String interpolation (substitution)
* Integrated with a powerful validation system

- including automatic type checking/conversion
- repeated sections
- and allowing default values

* All comments in the file are preserved
* The order of keys/sections is preserved
* No external dependencies
* Full Unicode support
* A powerful ``unrepr`` mode for storing basic datatypes

This is a bugfix and minor feature enhancement release. There is a
bugfix in `unrepr mode
`_, and
exception handling has been improved.

The full changelog is :

Changed error handling, if parsing finds a single error then that
error will be re-raised. That error will still have an ``errors`` and a
``config`` attribute. That means the error will be more comprehensible.

Fixed bug where '\n' terminated files could be truncated.

Bugfix in ``unrepr`` mode, it couldn't handle '#' in values.
(Thanks to Philippe Normand for the report.)

As a consequence of this fix, ConfigObj doesn't now keep inline
comments in ``unrepr`` mode. This is because the parser in the
`compiler package `_ doesn't
keep comments. {sm;:-)}

Error messages are now more useful. They tell you the number of
parsing errors and the line number of the first error. (In the case of
multiple errors.)

Line numbers in exceptions now start at 1, not 0.

Errors in ``unrepr`` mode are now handled the same way as in the
normal mode. The errors stored will be an ``UnreprError``.

There is also a proposal to support `PEP 292
`_ string substitution (which
is much better). This will be the target of the next release of
**ConfigObj**.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: mutable member, bug or ...

[Bruno Desthuilliers]

Sambo a écrit :
> By accident I assigned int to a class member 'count' which was 
> initialized to (empty) string and had no error till I tried to use it as 
> string, obviously. Why was there no error on assignment( near the end ).

Python is dynamically typed - which means that it's not the name that 
holds type info, but the object itself. names are just, well, names...

BTW, I failed to see where you assigned an int to the class attribute 
'count'. I just saw a try to call a string - which should raise a TypeError.

> class Cgroup_info:

Do yourself (and anyone having to work on or with your code) a favour: 
use new-style classes (ie : inherit from 'object'). And FWIW, the 
convention for class names is CamelCase - preferably without MS-like 
hungarian annotation.

>group_name = ""
>count = "0"  #last time checked and processed/retrieved
>first = "0"
>last = ""
>retrieval_type = ""# allways , ask( if more than some limit), 
> none
>date_checked = ""
>time_checked = ""
>new_count = ""
>new_first = ""
>new_last = ""
> # local storage maintanance vars
>pointer_file = ""
>message_file = ""
> #maintanance vars   cur_mess_num = 0
>cur_mess_id = ""

All these are *class* attributes (meaning they belong to the class 
object itself, not to instances). I really doubt this is what you want. 
If you hope to have all the above as instance attributes, you must 
assign them to the instance (usually in the __init__() method, which 
main purpose is to initialize the newly created instance.

>def __init__( self ):
>group_name = ""

this creates a local variable 'group_name', bound to an empty string. 
Using the reference to the current instance (usually named 'self', and 
always passed in as first param) is *not* optional.

>count = "0"  #last time checked and processed/retrieved

and this creates a local variable 'count', bound to string '0'.

Of course, both are lost as soon as the __init__() returns.

>def get_count( self ):
>print self.count, type( self.count )
>return string.atoi( self.count, 10 )

the string module is mostly deprecated. Use str object methods instead - 
  or if you just want to create an int from it's representation as a 
string, int(self.count).

> class server_info:
>def "(server_info::)"get_group_stat( self, grp ):

invalid syntax.

>   gr_info = Cgroup_info()

and a problem with indentation here.

>gr_info.group_name = grp

Tthis create a new instance attribute "group_name" on the gr_info 
object. This instance attribute will shadow the class attribute of the 
same name.

Also, FWIW, if you always know the value for group_name when 
instanciating a Cgroup_info object, you might as well pass it to the 
initializer.

>try:
>ind = self.group_list.index( grp )

The common convention for indices in each and every language is 'i'. If 
you really want a meaningful name, then group_index would be better.

Also, for this kind of lookups, dicts are really faster than lists.

>except ValueError:
>gr_info.count(0)

I didn't see any method "count()" in the declaration of class 
CGroup_info. I saw an attribute named "count", but it was bound to a 
string - which is not callable.

>return ( gr_info )

parenthesis here are useless (and FWIW, they would be just as useless in 
C++).

>print ind
>if len( self.group_list[ind].split() ) == 4:
>gr_info.count = self.group_list[ind].split()[1]
>gr_info.first = self.group_list[ind].split()[2]
>gr_info.last = self.group_list[ind].split()[3]

group_list[ind] is the same as grp, isn't it ? if so, using grp directly 
might be much more efficient *and* much more readable.

Also, you're calling 4 times the same method. This is highly 
inefficient. Try this instead:
parts = grp.split()
if len(parts) == 4:
  gr_info.count, gr_info.first, gr_info.last = parts[1:]


> else:
>gr_info.count = gr_info.first = gr_info.last = "0"

This style of "chained assignment" can be a real gotcha in Python. In 
this case, it is safe since "0" is immutable. But using a mutable object 
instead would lead to probably unexpected results. Try this:

a = b = []
a.append(1)
print b

You have to understand that Python "variables" (the correct name is 
"bindings") are just the association (in a given namespace) of a name 
and a *reference* (kind of a smart pointer) to an object.

>return( gr_info )   

Here's a possible rewrite of your code. It's certainly not how it should 
be done, but (apart from going into wild guesses) it's difficult to come 
up with anything better without knowing the specs. Anyway, it should 
help you grasp a more pythonic way to do things:

class GroupInfo(object):

def __init__(self, group_name, count="0", first="0", last=""):
self.group_name = group_name
self.count = count  #la

Re: Where is the ucs-32 codec?

[M�ta-MCI]

Hi!

Look at: http://cjkpython.berlios.de   (iconvcodec)

(Serge Orlov has built a version for Python 2.4 "special for me"; thanks to 
him).


@-salutations
-- 
Michel Claveau


-- 
http://mail.python.org/mailman/listinfo/python-list

Re: [OT] in python , could I accomplish the purpose that "a=Console.read()" used in C?

[Bruno Desthuilliers]

python a écrit :
> in python , could I accomplish the purpose that "a=Console.read()" used
> in C?


There's nothing like "Console.read()" in ansi-C.


(see Dennis's post for the answer to your question)
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: re beginner

[John Machin]

On 5/06/2006 10:38 AM, Bruno Desthuilliers wrote:
> SuperHik a écrit :
>> hi all,
>>
>> I'm trying to understand regex for the first time, and it would be 
>> very helpful to get an example. I have an old(er) script with the 
>> following task - takes a string I copy-pasted and wich always has the 
>> same format:
>>
>>  >>> print stuff
>> Yellow hat2Blue shirt1
>> White socks4Green pants1
>> Blue bag4Nice perfume3
>> Wrist watch7Mobile phone4
>> Wireless cord!2Building tools3
>> One for the money7Two for the show4
>>
>>  >>> stuff
>> 'Yellow hat\t2\tBlue shirt\t1\nWhite socks\t4\tGreen pants\t1\nBlue 
>> bag\t4\tNice perfume\t3\nWrist watch\t7\tMobile phone\t4\nWireless 
>> cord!\t2\tBuilding tools\t3\nOne for the money\t7\tTwo for the show\t4'
>>
>> I want to put items from stuff into a dict like this:
>>  >>> print mydict
>> {'Wireless cord!': 2, 'Green pants': 1, 'Blue shirt': 1, 'White 
>> socks': 4, 'Mobile phone': 4, 'Two for the show': 4, 'One for the 
>> money': 7, 'Blue bag': 4, 'Wrist watch': 7, 'Nice perfume': 3, 'Yellow 
>> hat': 2, 'Building tools': 3}
>>
>> Here's how I did it:
>>  >>> def putindict(items):
>> ... items = items.replace('\n', '\t')
>> ... items = items.split('\t')
>> ... d = {}
>> ... for x in xrange( len(items) ):
>> ... if not items[x].isdigit(): d[items[x]] = int(items[x+1])
>> ... return d
>>  >>>
>>  >>> mydict = putindict(stuff)
>>
>>
>> I was wondering is there a better way to do it using re module?
>> perheps even avoiding this for loop?
> 
> There are better ways. One of them avoids the for loop, and even the re 
> module:
> 
> def to_dict(items):
> items = items.replace('\t', '\n').split('\n')

In case there are leading/trailing spaces on the keys:

items = [x.strip() for x in items.replace('\t', '\n').split('\n')]

> return dict(zip(items[::2], map(int, items[1::2])))
> 
> HTH

Fantastic -- at least for the OP's carefully copied-and-pasted input.
Meanwhile back in the real world, there might be problems with multiple 
tabs used for 'prettiness' instead of 1 tab, non-integer values, etc etc.
In that case a loop approach that validated as it went and was able to 
report the position and contents of any invalid input might be better.
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Proposed new PEP: print to expand generators

[Bruno Desthuilliers]

James J. Besemer a écrit :
> 
(snip)
> 
> PEP -- EXTEND PRINT TO EXPAND GENERATORS
> 
> NUTSHELL
> 
> I propose that we extend the semantics of "print" such that if the 
> object to be printed is a generator then print would iterate over the 
> resulting sequence of sub-objects and recursively print each of the 
> items in order.
> 

Please, don't:

from itertools import cycle
def mygen():
 return cycle('this is a very bad idea'.split())


-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Using print instead of file.write(str)

[Bruno Desthuilliers]

Tim Roberts a écrit :
> Bruno Desthuilliers <[EMAIL PROTECTED]> wrote:
> 
> 
>>Sion Arrowsmith a écrit :
>>
(snip)
>>>"more flexible"? More convenient, yes. More powerful, maybe. But I
>>>don't see more flexible. Everything print can to stdout.write() can
>>>do. The reverse isn't true. eg (this appears to be a FAQ on this
>>>group, although I can't find it in the FAQ):
>>>
>>>for x in range(10):
>>>sys.stdout.write(str(x))
>>>
>>>to print:
>>>
>>>0123456789
>>
>>The reverse isn't true ???
>>
>>  print "".join(str(x) for x in range(10))
>  
> What he meant it that it is impossible to produce "0123456789" using 10
> separate print statements, while it IS possible with 10 separate writes.

why on earth would someone try to use 10 consecutive I/O operations on 
the same stream when it can be done with 1 ???
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Using print instead of file.write(str)

[Bruno Desthuilliers]

John Machin a écrit :
(snip)
> ... or was that a rhetorical question?

It was.
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: deleting texts between patterns

[John Machin]

On 5/06/2006 2:51 AM, Baoqiu Cui wrote:
> John Machin <[EMAIL PROTECTED]> writes:
> 
>> Uh-oh.
>>
>> Try this:
>>
> pat = re.compile('(?<=abc\n).*?(?=xyz\n)', re.DOTALL)
> re.sub(pat, '', linestr)
>> 'blahfubarabc\nxyz\nxyzzy'
> 
> This regexp still has a problem.  It may remove the lines between two
> lines like 'aaabc' and 'xxxyz' (and also removes the first two 'x's in
> 'xxxyz').
> 
> The following regexp works better:
> 
>   pattern = re.compile('(?<=^abc\n).*?(?=^xyz\n)', re.DOTALL | re.MULTILINE)
> 

You are quite correct. Your reply, and the rejoinder below, only add to 
the proposition that regexes are not necessarily the best choice for 
every text-processing job :-)

Just in case the last line is 'xyz' but is not terminated by '\n':

pattern = re.compile('(?<=^abc\n).*?(?=^xyz$)', re.DOTALL | re.MULTILINE)

Cheers,
John
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Installation Problem

[Marshall Dudley]

Warren Block wrote:

> Marshall Dudley <[EMAIL PROTECTED]> wrote:
> > Sorry, this is a FreeBSD system 4.8-RELEASE
> >
> > I found another set of documents that say to use the following to
> > install::
> >
> > python setup.py install
> >
> > but after running it, I still have the same problem.
>
> [top-posting trimmed, please don't do that]
>
> Doesn't the port work for 4.8?  It does work on FreeBSD 4.11, but there
> may have been changes to the ports system since 4.8.  (You should
> consider updating to 4.11.)
>
> There are several patch files in the FreeBSD port, including
> one to setup.py.
>
> The easiest way is to cvsup your ports tree and then
>
> cd /usr/ports/lang/python
> make
> make install
> make clean
>
> --
> Warren Block * Rapid City, South Dakota * USA

Now I have a python that runs, but the application I want to run it on
"denyhosts" gives me the following error:

Python >= 2.3 required.  You are using: 2.2.2 (#1, Jun  4 2006, 16:29:13)
[GCC 2.95.4 20020320 [FreeBSD]]

##

Visit http://www.python.org and download a more recent version of
Python.

You should install this version in addition to your current version
(rather than upgrading your current version) because your system might
depend on the current version.  After installing the newer version, for
instance version 2.4, simply invoke DenyHosts explicitly with the new
version of python, eg:

$ python2.4 ./denyhosts.py

##

Is it not possible to install the latest version of python on my FreeBSD
system?  Upgrading the FreeBSD is not an option since this is a production
system and everything else is working fine.

Marshall

-- 
http://mail.python.org/mailman/listinfo/python-list

Adding attribute to objetcs

[Miguel Galves]

Hello,I`m starting to learn python, and I hava a very good background in Javaand C/C++ programming. I was reading Dive into python chapter aboutOO and I saw that in python we can do the following:class Person:
    passjoe = new Person()joe.name = "Joe"joe.age = 13It seems that it is possible to add attributes to any object instancein run time, as in _javascript_. It seems to me that it can be a source
of errors. One that come in my mind is the follwing:class Person:
    name = ""

joe = new Person()
joe.nome = "Joe"The code above adds an attribute called nome,  but the programmer may think it's name.What is the real interest of this feature ? Is there a way to block this kind of error ?
Thanks,Miguel-- Miguel Galves - Engenheiro de ComputaçãoJá leu meus blogs hoje? Para geeks http://log4dev.blogspot.comPra pessoas normais
http://miguelgalves.blogspot.com"Não sabendo que era impossível, ele foi lá e fez..."
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: integer to binary...

[Bruno Desthuilliers]

Grant Edwards a écrit :
> On 2006-06-02, Bruno Desthuilliers <[EMAIL PROTECTED]> wrote:
> 
>>Grant Edwards a écrit :
>>
>>>On 2006-06-01, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
>>>
does anyone know a module or something to convert numbers like integer
to binary format ?
>>>
>>>They _are_ in binary format.
>>
>>Not really.
> 
> Yes, really.

No, not really.

>  Otherwise the bitwise boolean operations you
> demonstrated wouldn't work as shown.

Ho yes ?

> 
>(7).__class__
>>
>>
>>
>dir((7))
>>
>>['__abs__', '__add__', '__and__', '__class__', '__cmp__', '__coerce__',
>>'__delattr__', '__div__', '__divmod__', '__doc__', '__float__',
>>'__floordiv__', '__getattribute__', '__getnewargs__', '__hash__',
>>'__hex__', '__init__', '__int__', '__invert__', '__long__',
>>'__lshift__', '__mod__', '__mul__', '__neg__', '__new__', '__nonzero__',
>>'__oct__', '__or__', '__pos__', '__pow__', '__radd__', '__rand__',
>>'__rdiv__', '__rdivmod__', '__reduce__', '__reduce_ex__', '__repr__',
>>'__rfloordiv__', '__rlshift__', '__rmod__', '__rmul__', '__ror__',
>>'__rpow__', '__rrshift__', '__rshift__', '__rsub__', '__rtruediv__',
>>'__rxor__', '__setattr__', '__str__', '__sub__', '__truediv__', '__xor__']
>>
> 
> The fact that they impliment the xor operator is pretty much
> proof that integers are

... objects, instance of the int class. Not really what I'd call "binary 
format" !-)

Now if you go that way, it's of course true that everything on a 
computer ends up in a binary format It's true.

> stored in binary format -- xor is only
> defined for binary numbers.
> 
class Prisonner(object):
   def __xor__(self, other):
 return "I'm not a (binary) number, I'm a free man"

The fact that an object implements the xor operator is pretty much proof 
that the guy that wrote the class decided to implement the xor operator !-)

Grant, I of course agree that, *for practical means*, one can consider 
that Python's integer are "already in binary format" - for a definition 
of "binary format" being "you can do bitwise ops on them". But the truth 
is that Python integers are objects (in the OO meaning) holding integer 
values - not integer values themselves.
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: reordering elements of a list

[Roberto Bonvallet]

greenflame <[EMAIL PROTECTED]>:
> Roberto: I do not understand the first half of the last line of your
> code.

[mainlist[i - 1] for i in orderinglist] is a list made with the
elements of orderinglist, but instead of taking the actual value i
from the list, the value that is taken is mainlist[i - 1].

If orderinglist is [3, 4, 2, 1], then [mainlist[i - 1] for i in
orderinglist] is:

[mainlist[3 - 1], mainlist[4 - 1], mainlist[2 - 1], mainlist[1 - 1]]

Remember that indexing starts from 0.
-- 
Roberto Bonvallet
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: re beginner

[Paul McGuire]

"John Machin" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Fantastic -- at least for the OP's carefully copied-and-pasted input.
> Meanwhile back in the real world, there might be problems with multiple
> tabs used for 'prettiness' instead of 1 tab, non-integer values, etc etc.
> In that case a loop approach that validated as it went and was able to
> report the position and contents of any invalid input might be better.

Yeah, for that you'd need more like a real parser... hey, wait a minute!
What about pyparsing?!

Here's a pyparsing version.  The definition of the parsing patterns takes
little more than the re definition does - the bulk of the rest of the code
is parsing/scanning the input and reporting the results.

The pyparsing home page is at http://pyparsing.wikispaces.com.

-- Paul


stuff = 'Yellow hat\t2\tBlue shirt\t1\nWhite socks\t4\tGreen pants\t1\nBlue
bag\t4\tNice perfume\t3\nWrist watch\t7\tMobile phone\t4\nWireless
cord!\t2\tBuilding tools\t3\nOne for the money\t7\tTwo for the show\t4'
print "Original input string:"
print stuff
print

from pyparsing import *

# define low-level elements for parsing
itemWord = Word(alphas, alphanums+".!?")
itemDesc = OneOrMore(itemWord)
integer = Word(nums)

# add parse action to itemDesc to merge separate words into single string
itemDesc.setParseAction( lambda s,l,t: " ".join(t) )

# define macro element for an entry
entry = itemDesc.setResultsName("item") + integer.setResultsName("qty")

# scan through input string for entry's, print out their named fields
print "Results when scanning for entries:"
for t,s,e in entry.scanString(stuff):
print t.item,t.qty
print

# parse entire string, building ParseResults with dict-like access
results = dictOf( itemDesc, integer ).parseString(stuff)
print "Results when parsing entries as a dict:"
print "Keys:", results.keys()
for item in results.items():
print item
for k in results.keys():
print k,"=", results[k]


prints:

Original input string:
Yellow hat 2 Blue shirt 1
White socks 4 Green pants 1
Blue bag 4 Nice perfume 3
Wrist watch 7 Mobile phone 4
Wireless cord! 2 Building tools 3
One for the money 7 Two for the show 4

Results when scanning for entries:
Yellow hat 2
Blue shirt 1
White socks 4
Green pants 1
Blue bag 4
Nice perfume 3
Wrist watch 7
Mobile phone 4
Wireless cord! 2
Building tools 3
One for the money 7
Two for the show 4

Results when parsing entries as a dict:
Keys: ['Wireless cord!', 'Green pants', 'Blue shirt', 'White socks', 'Mobile
phone', 'Two for the show', 'One for the money', 'Blue bag', 'Wrist watch',
'Nice perfume', 'Yellow hat', 'Building tools']
('Wireless cord!', '2')
('Green pants', '1')
('Blue shirt', '1')
('White socks', '4')
('Mobile phone', '4')
('Two for the show', '4')
('One for the money', '7')
('Blue bag', '4')
('Wrist watch', '7')
('Nice perfume', '3')
('Yellow hat', '2')
('Building tools', '3')
Wireless cord! = 2
Green pants = 1
Blue shirt = 1
White socks = 4
Mobile phone = 4
Two for the show = 4
One for the money = 7
Blue bag = 4
Wrist watch = 7
Nice perfume = 3
Yellow hat = 2
Building tools = 3


-- 
http://mail.python.org/mailman/listinfo/python-list

Re: C# equivalent to range()

[Neuruss]

Delaney, Timothy (Tim) wrote:
> Well, there are reasons to reply to a message stating that it's not on-topic 
> for the group. The most common reaction to receiving no replies is to start a 
> new thread petulantly asking why there were no answers to the original 
> thread. If that one gets no replies the most common reaction is start another 
> new thread stating that Python sucks, the newsgroup sucks, etc.
>
> Not saying that this is what would have happened in this case, but it is the 
> most common sequence of events. Better to head it off before it happens. At 
> least any upset replies tend to be restricted to the one thread ;)
>
> Unfortunately, posting a good response, whilst apparently helpful, tends to 
> encourage further off-topic postings :(
>
> Tim Delaney

Tim,

I don't think it was entirely off topic, although I understand your
point.
It happens that I'm using Ironpython, and I wanted to improve the
performance of a script by writing a c# extension.
Writing extensions in other languages (c, c++ and now c#) is a common
practice amongst python programers, and that was the purpose of my
question.

I asked especifically the equivalence of a couple of python features in
this language.
And I did it here, because chances were that someone would understand
what I was asking, (which was how to translate those python features
into another language).

I could have asked this question in a c# related forum, but then I
should have had to explain how "range" and "extend" work in python...

Actualy, someone replied with a couple of lines, and this was just what
I wanted!
That person was very kind and I'm sure it didn't take more than a few
seconds to write his reply. I'm sure he was satisfied by helping me,
and I was satisfied too by his kind reply.

What about the others?
Are they worried about the storage limit of this forum perhaps?
Or it was the wasted bandwidth?
What was exactly the reason for being that annoyed? Am I forcing them
to read my question or to post a reply?

I grant that perhaps I should have explained why I needed this advice.
But I'm not using this forum to learn another thing. I am a (budding)
python programmer looking for a solution, and my question was very
especific and to the point.

Anyway, if someone still feels that the question is off topic, there
are better ways to point it out (as you're doing now).

If these people's life suck, I suggest they buy a punching bag to
discharge their frustation. I don't think this forum is the best place
for doing it.

Regards,
Neuruss

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Max function question: How do I return the index of the maximum value of a list?

[Steven Bethard]

jj_frap wrote:
> I'm new to programming in Python and am currently writing a three-card
> poker simulator. I have completed the entire simulator other than
> determining who has the best hand (which will be far more difficult
> than the aspects I've codes thus far)...I store each player's hand in a
> list of hand objects and I determine hand strength via a handstrength
> list with one element for each player.
> 
> When I try to print the "winner" (I've not coded for kicker strength
> and ties yet) via the max function, it returns the maximum value in the
> list rather than the index associated with that value.
> 
> How do I return the index?

Can you do something like::

 max_val, max_index = max((x, i) for i, x in enumerate(my_list))

?  If any two "x" values are equal, this will return the one with the 
lower index.  Don't know if that matters to you.

STeVe
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Max function question: How do I return the index of the maximum value of a list?

[Robert Kern]

Steven Bethard wrote:
> Can you do something like::
> 
>  max_val, max_index = max((x, i) for i, x in enumerate(my_list))
> 
> ?  If any two "x" values are equal, this will return the one with the 
> lower index.  Don't know if that matters to you.

Wouldn't it return the one with the highest index?

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: re beginner

[John Machin]

On 5/06/2006 10:07 AM, Paul McGuire wrote:
> "John Machin" <[EMAIL PROTECTED]> wrote in message
> news:[EMAIL PROTECTED]
>> Fantastic -- at least for the OP's carefully copied-and-pasted input.
>> Meanwhile back in the real world, there might be problems with multiple
>> tabs used for 'prettiness' instead of 1 tab, non-integer values, etc etc.
>> In that case a loop approach that validated as it went and was able to
>> report the position and contents of any invalid input might be better.
> 
> Yeah, for that you'd need more like a real parser... hey, wait a minute!
> What about pyparsing?!
> 
> Here's a pyparsing version.  The definition of the parsing patterns takes
> little more than the re definition does - the bulk of the rest of the code
> is parsing/scanning the input and reporting the results.
> 

[big snip]

I didn't see any evidence of error handling in there anywhere.


-- 
http://mail.python.org/mailman/listinfo/python-list

Lots of orphaned PyCon wiki pages...

[skip]

Over the past couple days I've been trying to reduce the large number of
orphaned wiki pages, deleting many, stitching many others back into the
fabric.  There are a bunch of orphaned PyCon-related pages, mostly subpages
of PyCon2005 and PyCon2006.  Would someone with PyCon-fu want to check them
out and decide their fate?  If so, visit

http://wiki.python.org/moin/OrphanedPages

and scroll down to the "P" section.

Thanks,

Skip
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: re beginner

[Paul McGuire]

"John Machin" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> On 5/06/2006 10:07 AM, Paul McGuire wrote:
> > "John Machin" <[EMAIL PROTECTED]> wrote in message
> > news:[EMAIL PROTECTED]
> >> Fantastic -- at least for the OP's carefully copied-and-pasted input.
> >> Meanwhile back in the real world, there might be problems with multiple
> >> tabs used for 'prettiness' instead of 1 tab, non-integer values, etc
etc.
> >> In that case a loop approach that validated as it went and was able to
> >> report the position and contents of any invalid input might be better.
> >
> > Yeah, for that you'd need more like a real parser... hey, wait a minute!
> > What about pyparsing?!
> >
> > Here's a pyparsing version.  The definition of the parsing patterns
takes
> > little more than the re definition does - the bulk of the rest of the
code
> > is parsing/scanning the input and reporting the results.
> >
>
> [big snip]
>
> I didn't see any evidence of error handling in there anywhere.
>
>
Pyparsing has a certain amount of error reporting built in, raising a
ParseException when a mismatch occurs.

This particular "grammar" is actually pretty error-tolerant.  To force an
error, I replaced "One for the money" with "1 for the money", and here is
the exception reported by pyparsing, along with a diagnostic method,
markInputline:


stuff = 'Yellow hat\t2\tBlue shirt\t1\nWhite socks\t4\tGreen pants\t1\nBlue
bag\t4\tNice perfume\t3\nWrist watch\t7\tMobile phone\t4\nWireless
cord!\t2\tBuilding tools\t3\nOne for the money\t7\tTwo for the show\t4'
badstuff = 'Yellow hat\t2\tBlue shirt\t1\nWhite socks\t4\tGreen
pants\t1\nBlue bag\t4\tNice perfume\t3\nWrist watch\t7\tMobile
phone\t4\nWireless cord!\t2\tBuilding tools\t3\n1 for the money\t7\tTwo for
the show\t4'
pattern = dictOf( itemDesc, integer ) + stringEnd
print pattern.parseString(stuff)
print
try:
print pattern.parseString(badstuff)
except ParseException, pe:
print pe
print pe.markInputline()

Gives:
[['Yellow hat', '2'], ['Blue shirt', '1'], ['White socks', '4'], ['Green
pants', '1'], ['Blue bag', '4'], ['Nice perfume', '3'], ['Wrist watch',
'7'], ['Mobile phone', '4'], ['Wireless cord!', '2'], ['Building tools',
'3'], ['One for the money', '7'], ['Two for the show', '4']]

Expected stringEnd (at char 210), (line:6, col:1)
>!<1 for the money 7   Two for the show4

-- Paul


-- 
http://mail.python.org/mailman/listinfo/python-list

Freezing a static executable

[Will Ware]

I am trying to freeze a static executable. I built a static Python
executable this way:
./configure --disable-shared --prefix=/usr/local
make
make install
Even that didn't give me a really static executable, though:
$ ldd /usr/local/bin/python
linux-gate.so.1 =>  (0xe000)
libpthread.so.0 => /lib/tls/libpthread.so.0 (0xb7f44000)
libdl.so.2 => /lib/libdl.so.2 (0xb7f4)
libutil.so.1 => /lib/libutil.so.1 (0xb7f3c000)
libm.so.6 => /lib/tls/libm.so.6 (0xb7f17000)
libc.so.6 => /lib/tls/libc.so.6 (0xb7de9000)
/lib/ld-linux.so.2 (0xb7f7)
Then I typed this:
/usr/local/bin/python
/home/wware/Python-2.4.1/Tools/freeze/freeze.py foo.py
ldd foo
$ ldd foo
linux-gate.so.1 =>  (0xe000)
libpthread.so.0 => /lib/tls/libpthread.so.0 (0xb7f5a000)
libdl.so.2 => /lib/libdl.so.2 (0xb7f56000)
libutil.so.1 => /lib/libutil.so.1 (0xb7f52000)
libm.so.6 => /lib/tls/libm.so.6 (0xb7f2d000)
libc.so.6 => /lib/tls/libc.so.6 (0xb7dff000)
/lib/ld-linux.so.2 (0xb7f86000)
What stupid thing am I doing wrong?
TIA for any advice
Will Ware

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: C# equivalent to range()

[Neuruss]

Dennis Lee Bieber wrote:
>   What most of us saw was a blunt request on how to implement a Python
> construct in some other language that may not be familiar to us.

I'm curious, who are "us"?

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Python less error-prone than Java

[Ilpo Nyyssönen]

"Kaz Kylheku" <[EMAIL PROTECTED]> writes:

> Buggy library code is what prompted that article.

Yes, but it is an error type that happens very rarely still. And so it
seems that very few programs even notice that bug in that library. 

> Except when you feed those programs inputs which are converted to
> integers which are then fed as domain values into some operation that
> doesn't fit into the range type.

If the input value range is limited, you want to get an error, if out
of range value is given. If you want to handle unlimited values, you
really need to take a look that you can do it. Think for example
storing such value to a database.

>> 1. null pointer errors
>> 2. wrong type (class cast in Java, some weird missing attribute in python)
>> 3. array/list index out of bounds
>>
>> First and third ones are the same in about every language.
>
> ... other than C and C++, where their equivalents just crash or stomp
> over memory, but never mind; who uses those? ;)

It is not different. Your crash can tell you that it was a null
pointer. Your crash can tell you that you stomped over memory. You
just get the information about the error in different way.

> Instead of this stupid idea of pointers or references having a null
> value, you can make a null value which has its own type, and banish
> null pointers.

Yes and I actually think that as bad thing. It is nice to be able to
tell the difference between null pointer and wrong type. Of course if
the error message tells you that you had null there, it is not a
problem, but what if you somehow lose the error message and get only
the exception class name? (Yes, you should always keep the message
too, but it does happen.)

-- 
Ilpo Nyyssönen # biny # /* :-) */
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Max function question: How do I return the index of the maximum value of a list?

[Steven Bethard]

Robert Kern wrote:
> Steven Bethard wrote:
>> Can you do something like::
>>
>>  max_val, max_index = max((x, i) for i, x in enumerate(my_list))
>>
>> ?  If any two "x" values are equal, this will return the one with the 
>> lower index.  Don't know if that matters to you.
> 
> Wouldn't it return the one with the highest index?

Yes sorry.  Mentally switched my min and max calls.

Thanks for the catch.

Steve
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: C# equivalent to range()

[Erik Max Francis]

Neuruss wrote:

> Dennis Lee Bieber wrote:
>>  What most of us saw was a blunt request on how to implement a Python
>> construct in some other language that may not be familiar to us.
> 
> I'm curious, who are "us"?

The regular readers of comp.lang.python.  If you don't think we haven't 
seen this a zillion times before, you're kidding yourself.

If you want help on a language, ask in that language's newsgroup/mailing 
list/forum/whatever.

It surprises me how often people don't ask useful questions, or 
deliberately and knowingly ask questions in the wrong places, and then 
actually _defend_ their actions after they're politely but firmly 
informed how to fix the problem.  You're really not making yourself look 
any better by continuing this thread ...

-- 
Erik Max Francis && [EMAIL PROTECTED] && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis
   Democritus may have come from Abdera, but he was no dummy.
   -- Carl Sagan
-- 
http://mail.python.org/mailman/listinfo/python-list

attribute error using fnmatch

[s99999999s2003]

hi
i have script like this:

from fnmatch import fnmatch
from glob import glob

...
f = ['file1','file2','file3']
r = "d:\\somepath"
pat = "*.bat"
listof_files = [i for i in f if not fnmatch(os.path.join(r,i),pat) and
os.path.isfile(os.path.join(r,i))]
...
..

I get  this error:
  File "C:\Python24\Lib\fnmatch.py", line 37, in fnmatch
pat = os.path.normcase(pat)
  File "C:\Python24\lib\ntpath.py", line 42, in normcase
return s.replace("/", "\\").lower()
AttributeError: replace

But when i do everything in interactive, there is no problem.. What
could be wrong with the script?
My purpose is to find a list of files that does not match pat...
thanks

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: Is device Connected Windows?

[placid]

Tim Golden wrote:
> [placid]
>
> | Just wondering is there a way (not brute force) to check if a usb
> | storage device is connected?
>
> Hmmm. How do you identify "a usb storage device" to know that
> it is or isn't connected?
>
> You can certainly do something useful with wmi. eg,
>
> 
> import wmi
>
> c = wmi.WMI ()
> for usb_disk in c.Win32_DiskDrive (InterfaceType="USB"):
>   print usb_disk.Caption
>   print usb_disk.PNPDeviceID
>
> 
>
> Now, assuming that the PNPDeviceID is unique enough for
> your purpose, you could probably do something with it
> to keep hold of it and then check later whether the
> same device is still inserted. One possibility is
> to use a WMI watcher to spot when devices are removed:
>
> 
> import wmi
>
> c = wmi.WMI ()
> usb_watcher = c.watch_for (
>   notification_type="Deletion",
>   wmi_class="Win32_DiskDrive",
>   delay_secs=2,
>   InterfaceType="USB"
> )
>
> while True:
>   usb_removed = usb_watcher () # can optionally timeout
>   print usb_removed.PNPDeviceID
>
> 
>

Thanks mate, this is what i was after, i can work my way through here.

-- 
http://mail.python.org/mailman/listinfo/python-list

Re: attribute error using fnmatch

[Fredrik Lundh]

[EMAIL PROTECTED] wrote:

> listof_files = [i for i in f if not fnmatch(os.path.join(r,i),pat) and
> os.path.isfile(os.path.join(r,i))]
> ...
> ..
> 
> I get  this error:
>   File "C:\Python24\Lib\fnmatch.py", line 37, in fnmatch
> pat = os.path.normcase(pat)
>   File "C:\Python24\lib\ntpath.py", line 42, in normcase
> return s.replace("/", "\\").lower()
> AttributeError: replace
> 
> But when i do everything in interactive, there is no problem.. What
> could be wrong with the script?

nothing, from what I can tell.

did you verify that the code you posted really have the problem (it does 
use the 'os' module which isn't important, and doesn't use 'glob' which 
is imported, so chances are that you messed something up on the way to 
comp.lang.python).

what do you get if you add

 print repr(pat), type(pat)

just before the list comprehension ?



-- 
http://mail.python.org/mailman/listinfo/python-list