s is fairly pedestrian as gotchas go, but it has bitten me:
If you are working with data that is representable as either an integer
or a string, choose one and stick to it. Treating it as both/either will
eventually lead to grief.
Or, in other words: 1 != '1'
--
John Gordon
In John Gordon writes:
> I'm writing an application that interacts with ldap, and I'm looking
> for advice on how to handle the connection. Specifically, how to
> close the ldap connection when the application is done.
> I wrote a class to wrap an LDAP conne
On Thu, 05 Apr 2012 10:15:03 -0400
John Posner wrote:
> On 4/4/2012 7:32 PM, Chris Angelico wrote:
> > Don't know if it's what's meant on that page by the += operator,
>
> Yes, it is.
>
> >> a=([1],)
> >> a[0].append(2) # This is fine
&
y difficult to find out how
to do at first. To get your test script working, you just need to flush stdout
from there; add:
sys.stdout.flush()
to your for loop above.
However, if there is a real process you need to use which you "can't modify",
then it seems you'll have to use one of the more complex solutions offered here.
Regards,
John
--
http://mail.python.org/mailman/listinfo/python-list
and <) to derive any of the other comparisons; but not to imply that a
class that only defines those two will automatically possess the others.
However, you can do that, with functools.total_ordering.
Regards,
John
--
http://mail.python.org/mailman/listinfo/python-list
ion. This can
stall servers.
9. Some libraries aren't thread-safe. Guess which ones.
10. Python 3 isn't upward compatible with Python 2.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
is method to support more appropriate behavior
if needed."
A related "gotcha" is knowing that "urllib" sucks and you should use
"urllib2".
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
modules?
How to package and distribute your own modules once they're finished?
How to install modules that other people have developed?
--
John Gordon A is for Amy, who fell down the stairs
gor...@panix.com B is for Bas
t on the EDVAC", for
background on how things work down at the bottom. But they're
no longer essential desk references for most programmers.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
this decision problem.
Can you suggest any paper/book/example about:
- scenario analysis in pyhon
- stochastic simulation in pyhon
- coping with uncertenises and risk in python (VaR, CVaR)?
Thanks in advance for any help.
John
--
http://mail.python.org/mailman/listinfo/python-list
works.
Don't use the "rotten egg" distribution system.
(http://packages.python.org/distribute/easy_install.html)
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
On 4/12/2012 10:41 AM, Roy Smith wrote:
Is there a simple way to deep merge two dicts? I'm looking for Perl's
Hash::Merge (http://search.cpan.org/~dmuey/Hash-Merge-0.12/Merge.pm)
in Python.
def dmerge(a, b) :
for k in a :
v = a[k]
if isinstance(v, dict) and k in b:
On Thu, 12 Apr 2012 12:35:21 -0600
Ian Kelly wrote:
> On Thu, Apr 12, 2012 at 11:59 AM, John Nagle wrote:
> > On 4/12/2012 10:41 AM, Roy Smith wrote:
> >>
> >> Is there a simple way to deep merge two dicts? I'm looking for Perl's
> >> Hash::Merge
On Fri, 13 Apr 2012 10:50:15 -0600
Ian Kelly wrote:
> On Fri, Apr 13, 2012 at 5:11 AM, John O'Hagan wrote:
> > I think you also have to check if a[k] is a dict before making the recursive
> > call, else for example dmerge({'a': 1}, {'a': {'b':
d where n < 5 or thereabouts. However, if it
doesn't happen when the command is issued, it happens when 'exit' is called.
Hopefully some of this is a clue.
Regards,
John
--
http://mail.python.org/mailman/listinfo/python-list
first one.
OTOH, "is" hangs on to both objects in order to compare them.
c.f.:
>>> l, m = [], []
>>> id(l) == id(m)
False
Is that right?
--
John
--
http://mail.python.org/mailman/listinfo/python-list
On Friday, April 20, 2012 12:34:46 PM UTC-7, Rotwang wrote:
> I believe it says somewhere in the Python docs that it's undefined and
> implementation-dependent whether two identical expressions have the same
> identity when the result of each is immutable
I was curious where that might be on my
s, like "None". You can't assign
to None, but you can assign to True, usually with
unwanted results. It's not clear why True and False
weren't locked down when None was.)
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
ings in everything in the other module, which often
results in a name clash.
Just do
import file_1
and, if desired
localnamefora = file_1.a
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
On Sunday, April 22, 2012 1:43:36 PM UTC-6, John Nagle wrote:
> On 4/20/2012 9:34 PM, john.tant...@gmail.com wrote:
> > On Friday, April 20, 2012 12:34:46 PM UTC-7, Rotwang wrote:
> >
> >> I believe it says somewhere in the Python docs that it's undefined and
> >
On 4/22/2012 3:17 PM, John Roth wrote:
On Sunday, April 22, 2012 1:43:36 PM UTC-6, John Nagle wrote:
On 4/20/2012 9:34 PM, john.tant...@gmail.com wrote:
On Friday, April 20, 2012 12:34:46 PM UTC-7, Rotwang wrote:
I believe it says somewhere in the Python docs that it's
undefine
On 4/22/2012 9:34 PM, Steven D'Aprano wrote:
On Sun, 22 Apr 2012 12:43:36 -0700, John Nagle wrote:
On 4/20/2012 9:34 PM, john.tant...@gmail.com wrote:
On Friday, April 20, 2012 12:34:46 PM UTC-7, Rotwang wrote:
I believe it says somewhere in the Python docs that it's und
t; have to force the creation of a temporary boxed object?
The concept of "object" vs. the implementation of objects is
one reason you don't necessarily want to expose the implementation.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
On 4/26/2012 4:45 AM, Adam Skutt wrote:
On Apr 26, 1:48 am, John Nagle wrote:
On 4/25/2012 5:01 PM, Steven D'Aprano wrote:
On Wed, 25 Apr 2012 13:49:24 -0700, Adam Skutt wrote:
Though, maybe it's better to use a different keyword than 'is' though,
due to the plain Eng
or i in iterable:
x = expensive_call(i)
if condition(x):
results.append(x)
--
John
--
http://mail.python.org/mailman/listinfo/python-list
re
copies of the Python interpreter. The threads are usually I/O bound,
but when they hit unusually long web pages, they go compute-bound
during parsing.)
Setting "sys.setcheckinterval" from the default to 1 seems
to have little effect. This is on Windows 7.
On 4/27/2012 6:25 PM, Adam Skutt wrote:
On Apr 27, 2:54 pm, John Nagle wrote:
I have a multi-threaded CPython program, which has up to four
threads. One thread is simply a wait loop monitoring the other
three and waiting for them to finish, so it can give them more
work to do. When the
On 4/27/2012 9:20 PM, Paul Rubin wrote:
John Nagle writes:
The code that stored them looked them up with "getaddrinfo()", and
did this while a lock was set.
Don't do that!!
Added a local cache in the program to prevent this.
Performance much improved.
Better to r
On 4/27/2012 9:55 PM, Paul Rubin wrote:
John Nagle writes:
I may do that to prevent the stall. But the real problem was all
those DNS requests. Parallizing them wouldn't help much when it took
hours to grind through them all.
True dat. But building a DNS cache into the applic
e sentence you quote sensibly
obviates repeating the semantics of "install", which have just been described
in detail in the immediately preceding paragraph. If it did repeat them,
wouldn't you mock the docs anyway, for redundancy?
Regards,
--
John
--
http://mail.python.org/mailman/listinfo/python-list
ges, it will be in the wrong
> hash bucket)."
[...]
How do function objects fit into this scheme? They have __hash__, __eq__, seem
to work as dict keys and are mutable. Is it because their hash value doesn't
change? Under what circumstances does an object's hash value change?
--
John
--
http://mail.python.org/mailman/listinfo/python-list
ot;Know who you're dealing with" system, SiteTruth.)
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
r than Ada, which requires it, few
languages handle such exceptions as language level
exceptions.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
data storage.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
I need to convert this to
> this: ['ksals', '', 'alsdkfj', '3', '']
That looks like a tuple which contains five strings. But you said it's
a string, so I'll believe you.
>>> x = "('ksals', '
g.multenterbox(msg1,title, fieldNames, choice)
> fieldNames has 5 fields.
If you just need to convert a tuple to a list, that's easy. Call the
built-in function list() and pass the tuple as an intializer:
>>> choice = ('ksals', '', 'alsdkfj', '
edorahosted.org/suds/
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
An HTML page for a major site (http://www.chase.com) has
some incorrect HTML. It contains
o do in cases where the boss is too FOSS for your taste, or whatever
the problem was.
Seems like a great deal of hurt has occurred, both to people and to the
project, just to save the administrative hassle of forking. In the words of the
hijacker, he was going to fork but "an opportunity pr
That's awful. There's no point in compressing six characters
with zlib. Zlib has a minimum overhead of 11 bytes. You just
made the data bigger.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
system for a
million item db is ridiculous even for prototyping.
Right. Steve Bellovin wrote that back when UNIX didn't have any
database programs, let alone free ones.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
On 5/7/2012 9:09 PM, Steve Howell wrote:
On May 7, 8:46 pm, John Nagle wrote:
On 5/6/2012 9:59 PM, Paul Rubin wrote:
Javierwrites:
Or not... Using directories may be a way to do rapid prototyping, and
check quickly how things are going internally, without needing to resort
to complex
r "TooLong". But that's not
enough; I also need to know the outer class name, i.e. "Question.TooShort"
or "Question.TooLong". How do I get the outer class name?
Thanks,
--
John Gordon A is for Amy, who fell down the stairs
gor...@panix.com B is for Basil, assaulted by bears
-- Edward Gorey, "The Gashlycrumb Tinies"
--
http://mail.python.org/mailman/listinfo/python-list
In John Gordon writes:
> class QuestionTooShortError(NetIDAppsError):
> """User entered a security question which is too short."""
> pass
> class QuestionTooLongError(NetIDAppsError):
> """User entered a security que
pyPortMidi as a way to send MIDI messages between software
packages on the same computer."
HTH,
John
--
http://mail.python.org/mailman/listinfo/python-list
be returned instead. """
Thanks for your help - and sorry again for such a naive question.
John T.
--
http://mail.python.org/mailman/listinfo/python-list
Thank you all for your help.
Greatly appreciated.
John
--
http://mail.python.org/mailman/listinfo/python-list
filename, turned out to really be
called pyeca.
Are there any rules about this kind of thing? (I did say "minor gripe".)
--
John
--
http://mail.python.org/mailman/listinfo/python-list
eyword can't be an expression" error.
The general syntax for assigning to a dictionary is:
my_dictionary[key] = value
What are you trying that isn't working?
--
John Gordon A is for Amy, who fell down the stairs
gor...@panix.
In msmucr
writes:
> Do I have something wrong or is it simply broken and unmaintained now?
We have no idea if you did anything wrong, because you didn't tell us
exactly what you did and exactly what error message you received.
--
John Gordon A is for Amy, who fell
me this value is the editor
> program to run.
This looks like a job for 'const':
parser.add_argument('-e', '--edit', help='open editor on log', nargs='?',
const="$EDITOR")
I think that does what you want.
HTH,
John
--
http://mail.python.org/mailman/listinfo/python-list
ss. I
also get the feeling I'm barking up the wrong tree. Any suggestion?
Thanks,
--
John
--
http://mail.python.org/mailman/listinfo/python-list
On Sat, 19 May 2012 09:15:39 +0100
Arnaud Delobelle wrote:
> On 19 May 2012 06:23, John O'Hagan wrote:
[...]
> >
> > How to generate only the distinct permutations of a sequence which are not
> > rotationally equivalent to any others? More precisely, to generate only
On Sat, 19 May 2012 04:21:35 -0400
Zero Piraeus wrote:
> :
>
> On 19 May 2012 01:23, John O'Hagan wrote:
> > How to generate only the distinct permutations of a sequence which are not
> > rotationally equivalent to any others? More precisely, to generate only the
>
9,200 baud is enough for you, don't worry about it.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
On 5/22/2012 2:07 PM, Paul Rubin wrote:
John Nagle writes:
If a device is registered as /dev/ttyUSBnn, one would hope that
the Linux USB insertion event handler, which assigns that name,
determined that the device was a serial port emulator. Unfortunately,
the USB standard device classes
ase of the first.
For a quoted alternative to regular expression syntax, see
SNOBOL or Icon. SNOBOL allows naming patterns, and those patterns
can then be used as components of other patterns. SNOBOL
is obsolete, but that approach produced much more readable
code.
It matches anything that looks like a mail user name followed by
an @ followed by anything that looks more or less like a domain name.
The domain name must contain at least one ".", and cannot end with
a ".", which is not strictly correct but usually works.
In <6e534661-0823-4c42-8f60-3052e43b7...@googlegroups.com>
"psaff...@googlemail.com" writes:
> How do I force the memory for these soup objects to be freed?
Have you tried deleting them, using the "del" command?
--
John Gordon A is for Amy,
able, you may be approaching the
problem incorrectly.
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
g that looks like a leak. It reported that there were 19 objects
which are unreachable and therefore are candidates for being collected.
What makes you think there is a leak?
--
John Gordon A is for Amy, who fell down the stairs
gor...@panix.com B is for Basil, assa
ters in position
0-5: ordinal not in range(128)
>>>
The HTTP library is trying to put the URL in the header as ASCII. Why
isn't "urllib2" handling that?
What does "urllib2" want? Percent escapes? Punycode?
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
Tarek,
There doesn't appear to be a function in stdlib to cover that particular case.
Doug Hellman has a nice section on finding service info here:
http://www.doughellmann.com/PyMOTW/socket/addressing.html
It wouldn't be "built-in", but it looks like it would be pretty simple to get
the in
On 6/12/2012 11:42 PM, Andrew Berg wrote:
On 6/13/2012 1:17 AM, John Nagle wrote:
What does "urllib2" want? Percent escapes? Punycode?
Looks like Punycode is the correct answer:
https://en.wikipedia.org/wiki/Internationalized_domain_name#ToASCII_and_ToUnicode
I haven't t
em as subprocesses. That way there would be fewer threads,
but each subprocess would be doing more work.
My question is, on a single core machine, what are the pros and cons of
threads vs subprocesses in a setup like this?
Thanks,
John
--
http://mail.python.org/mailman/listinfo/python-list
On Fri, 15 Jun 2012 11:51:01 -0400
Dave Angel wrote:
> On 06/15/2012 09:49 AM, John O'Hagan wrote:
> > I have a program in which the main thread launches a number of CPU-intensive
> > worker threads. For each worker thread two python subprocesses are started,
[...]
> &g
On Fri, 15 Jun 2012 16:34:57 -0400
Dennis Lee Bieber wrote:
> On Sat, 16 Jun 2012 03:24:13 +1000, John O'Hagan
> declaimed the following in
> gmane.comp.python.general:
>
>
> > I should have made it clear that I'm not using threads to speed anything
On Sat, 16 Jun 2012 13:27:45 -0400
Dennis Lee Bieber wrote:
> On Sat, 16 Jun 2012 20:01:12 +1000, John O'Hagan
> declaimed the following in
> gmane.comp.python.general:
>
> >
> > That looks like a possible way to do all the streams in a single thread,
&
3.x the equivalent of Python 2.x's input() function is eval(input()).
It poses the same security risk: acting on unchecked user data.
John Roth
> jmf
--
http://mail.python.org/mailman/listinfo/python-list
On 6/2/2011 4:40 AM, xDog Walker wrote:
On Wednesday 2011 June 01 10:34, John Nagle wrote:
I have a program which uses "feedparser". It occasionally hangs when
the network connection has been lost, and remains hung after the network
connection is restored.
My solution is to downloa
n%count==0 ]
print group('abcdefghij', 3) # ['abc', 'def', 'ghi', 'j']
print group('abcdefghijk' * 2, 7) # ['abcdefg', 'hijkabc',
'defghij', 'k']
print group('', 42) # []
-John
--
http://mail.python.org/mailman/listinfo/python-list
to try "new style" string formatting [1], which I think
is better than the "old style" in this particular case:
>>> "Testing {0:0{1}d}".format(42, 4)
'Testing 0042'
>>> "Testing {0:0{1}d}".format(42, 9)
'
ave a method and a list that are both called dogAppend. Try naming
one of them something different.
--
John Gordon A is for Amy, who fell down the stairs
gor...@panix.com B is for Basil, assaulted by bears
-- Edward Gorey, "
ference
If you're starting new, use 3.2. All code will eventually move to this
newer style, so you'll have to learn it eventually.
The only reason to use 2.6 is if you have to maintain an existing code
base that was written with 2.6 (or older).
--
John Gordon A is for Amy,
yping it by hand, specifically to avoid errors like this.
Please repost a transcript of your real session.
--
John Gordon A is for Amy, who fell down the stairs
gor...@panix.com B is for Basil, assaulted by bears
-- Edward Gorey, &
that's
what "hoisted" means in this context..
John Nagle
--
http://mail.python.org/mailman/listinfo/python-list
Based on what I've read, it seems os.rename is the proper function to
use, but I'm a little confused about the syntax. Basically I just want
to write a simple script that will back up my saved game files when I
run it. So I want it to copy a set of files/directories from a
location on my C:\ drive
On Jun 15, 9:33 am, Olivier LEMAIRE
wrote:
> You're right, I use Python 2.6.6
This works great in 2.6.5 and later (and probably earlier). You just
have to number your placeholders. The first set of braces formats i
(your value), the second set specifies the field with (i.e., 8):
>>> for i in xra
On Jun 17, 2:25 am, Gregory Ewing wrote:
> John Salerno wrote:
> > I want it to copy a set of files/directories from a
> > location on my C:\ drive to another directory on my E:\ drive. I don't
> > want to rename or delete the originals,
>
> It sounds like shutil
On Jun 17, 2:23 pm, Terry Reedy wrote:
> If you follow the second part of Greg's suggestion 'or one of the other
> related function in the shutil module', you will find copytree()
> "Recursively copy an entire directory tree rooted at src. "
Yeah, but shutil.copytree says:
"The destination dire
On Jun 17, 5:15 pm, Ethan Furman wrote:
> John Salerno wrote:
> > On Jun 17, 2:23 pm, Terry Reedy wrote:
>
> >> If you follow the second part of Greg's suggestion 'or one of the other
> >> related function in the shutil module', you will find copytree
Let's say I'm writing a game (really I'm just practicing OOP) and I
want to create a "Character" base class, which more specific classes
will subclass, such as Warrior, Wizard, etc. Which of the following
ways is better, or is there another way?
Note: I have in mind that when a specific subclass (
Whew, thanks for all the responses! I will think about it carefully
and decide on a way. I was leaning toward simply assigning the health,
resource, etc. variables in the __init__ method, like this:
def __init__(self, name):
self.name = name
self.health = 50
self.resource = 10
I never
On Jun 19, 8:52 pm, Chris Kaynor wrote:
> Having a character class (along with possibly player character, non-player
> character, etc), make sense; however you probably want to make stuff like
> health, resources, damage, and any other attributes not be handles by any
> classes or inheritance
I can't quite seem to find the answer to this anywhere. The book I'm
reading right now was written for Python 3.1 and doesn't use (object),
so I'm thinking that was just a way to force new-style classes in 2.x
and is no longer necessary in 3.x. Is that right?
(The documentation doesn't mention obj
On Jun 20, 8:33 pm, Benjamin Kaplan wrote:
> On Mon, Jun 20, 2011 at 6:26 PM, John Salerno wrote:
> > I can't quite seem to find the answer to this anywhere. The book I'm
> > reading right now was written for Python 3.1 and doesn't use (object),
> > so I
for the continuation lines?
(There was also discussion of this in a comp.lang.python thread last
year, subject: if, continuation and indentation, started May 27.)
John Y.
--
http://mail.python.org/mailman/listinfo/python-list
I'm working on the Project Euler exercises and I'm stumped on problem
3:
"What is the largest prime factor of the number 600851475143 ?"
Now, I've actually written functions to get a list of the factors of
any given number, and then another function to get the prime numbers
from that list. It wor
On Jun 21, 3:22 pm, Irmen de Jong wrote:
> On 21-06-11 22:10, Irmen de Jong wrote:
> [stuff]
>
> I didn't read the last paragraph of John's message until just now, and
> now realize that what I wrote is likely way too much information for
> what he asked.
> I'm sorry. Next time I'll read everythin
On Jun 21, 4:41 pm, Ian Kelly wrote:
> On Tue, Jun 21, 2011 at 3:09 PM, John Salerno wrote:
> > Don't worry, I was still unclear about what to do after reading all
> > the responses, even yours! But one thing that made me feel better was
> > that I wasn't havin
::sigh:: Well, I'm stuck again and it has to do with my get_factors
function again, I think. Even with the slight optimization, it's
taking forever on 20! (factorial, not excitement) :) It's frustrating
because I have the Python right, but I'm getting stuck on the math.
The problem:
"What is the
On Jun 21, 9:09 pm, Paul Rubin wrote:
> John Salerno writes:
> > It's frustrating because I have the Python right, but I'm getting
> > stuck on the math
> > "What is the smallest positive number that is evenly divisible by all
> > of the numbers f
On Jun 21, 10:02 pm, Mel wrote:
> John Salerno wrote:
> > ::sigh:: Well, I'm stuck again and it has to do with my get_factors
> > function again, I think. Even with the slight optimization, it's
> > taking forever on 20! (factorial, not excitement) :) It'
t, what did you specifically have in mind?
--
John Gordon A is for Amy, who fell down the stairs
gor...@panix.com B is for Basil, assaulted by bears
-- Edward Gorey, "The Gashlycrumb Tinies"
--
http://mail.python.org/mailman/listinfo/python-list
After I've run the re.search function on a string and no match was
found, how can I access that string? When I try to print it directly,
it's an empty string, I assume because it has been "consumed." How do
I prevent this?
It seems to work fine for this 2.x code:
import urllib.request
import re
On Jun 23, 3:47 pm, Ian Kelly wrote:
> On Thu, Jun 23, 2011 at 1:58 PM, John Salerno wrote:
> > After I've run the re.search function on a string and no match was
> > found, how can I access that string? When I try to print it directly,
> > it's an empty strin
On Jun 23, 4:47 pm, "Thomas L. Shinnick"
wrote:
> There is also
> print(match_obj.string)
> which gives you a copy of the string searched. See end of section
> 6.2.5. Match Objects
I tried that, but the only time I wanted the string printed was when
there *wasn't* a match, so the match ob
t;cn=My-Group-1,ou=Groups,o=CUST", ldap.SCOPE_BASE)
for result in results:
result_dn = result[0]
result_attrs = result[1]
if "member" in result_attrs:
for member in result_attrs["member"]:
print member
ldapClient.unbind_s()
--
John Gordo
In Cousin Stanley
writes:
> How or why this behavior was cultivated
> and continues to spread is mind boggling
The behavior of writing in all caps, or the behavior of equating such
writing with shouting?
--
John Gordon A is for Amy, who fell down the stai
In
pipehappy writes:
> Why people want print() instead of print str? That's not a big deal
> and the old choice is more natural. Anyone has some clue?
Because the new Python uses print(). print "str" is the old way.
--
John Gordon A is for Amy, who
401 - 500 of 9356 matches
Mail list logo
