Re: BASIC vs Python
Adam DePrince wrote: On Fri, 2004-12-17 at 09:25, Steve Holden wrote: Or make any given standard python object accessible from MS Excel in 2 minutes. What you describe is a political, not technical, challenge. What I describe is a daily costumer demand. Like or not, the world uses Excel and costumers want to access apps from it. -- Greg -- http://mail.python.org/mailman/listinfo/python-list
Re: better lambda support in the future?
"Bengt Richter" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Looks like your standard pattern could be updated:
>
> >>> dispatch = {}
> >>>
> >>> def dispvia(name):
> ... def _(f, name=name):
> ... dispatch[name] = f
> ... return f
> ... return _
> ...
> >>> @dispvia('a')
> ... def handle_a(): pass
> ...
> >>> @dispvia('b')
> ... def handle_b(): pass
> ...
> >>> @dispvia('c')
> ... def handle_c(): pass
> ...
> >>> for t in sorted(dispatch.items()): print '%5s: %r'%t
> ...
> a:
> b:
> c:
To avoid the redundancy of 'a' and '_a', etc, how about (untested):
def dispvia(f):
dispatch[f.__name__.split('_')[1]] = f
return f
? (Don't have 2.4 loaded yet)
Terry J. Reedy
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Re: BASIC vs Python
Andrew Dalke wrote: Huh? I'm talking about my views of myself. I said that BASIC was a programming language I could learn without access to anyone else, on a microcomputer circa 1982. All I had was the book that came with the computer, and after a while a book on BASIC games. The machine I had was a TI 99/4A. My Dad got it because the marketing said "it's a 16 bit processor which is the wave of the future; the other machine only have 8 bit processors." It came with BASIC. LOGO was available, now that others reminded Seems that we had the same career. :-) I liked the TI 99/4A. Mine is still running, sometimes :-) TI really made a good job in producing a educational machine. It was simple, and you could make good results with little effort. Same with python today. And whow knows, without the TI, would I post here right now? -- Greg -- http://mail.python.org/mailman/listinfo/python-list
Re: Cool object trick
On Sat, 18 Dec 2004 08:39:47 +0100, "Fredrik Lundh" <[EMAIL PROTECTED]> wrote:
>Carl Banks wrote:
>
>> For example:
>>
>> .def lookup_reference(key):
>> .
>> .return Bunch(title=title,author=author,...)
>>
>> The code quickly and easily returns a object with the desired keys.
>> The code that calls this function would access the return values
>> directly, like this:
>>
>> .m = lookupreference()
>> .print "%s was written by %s" % (m.title,m.author)
>>
>> You could still use a dict for this, but a Bunch class neater and more
>> concise (not to mention less typing).
>
>this is how your example looks in Python:
>
>def lookup_reference(key):
>...
>return dict(title=title, author=author, ...)
>
>m = lookup_reference(...)
>print "%(title)s was written by %(author)s" % m
>
>(if you fix the bug in your example, and count the characters, you'll find
>that my example is a bit shorter)
>
>with enough keys, you can also save typing by using dummy object instead
>of a dictionary, and getting rid of the locals in lookup_reference:
>
>def lookup_reference(key):
>m = object()
>m.title = ... assign directly to return struct members ...
>m.author = ...
>return m
>
>m = lookup_reference(...)
>print "%(title)s was written by %(author)s" % vars(m)
>
>>> m = object()
>>> m.title = 'not so fast ;-)'
Traceback (most recent call last):
File "", line 1, in ?
AttributeError: 'object' object has no attribute 'title'
>>> m=type('',(),{})()
>>> m.title = 'not so fast ;-)'
>>> m.title
'not so fast ;-)'
Regards,
Bengt Richter
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Re: Is this a good use for lambda
"Charlie Taylor" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > > I find that I use lambda functions mainly for callbacks to things like > integration or root finding routines as follows. > > flow = integrate(lambda x: 2.0*pi * d(x)* v(x) * sin(a(x)),xBeg, xEnd) > > root = findRoot(xBeg, xEnd, > lambda x: y2+ lp*(x-x2) -wallFunc( x )[0], tolerance=1.0E-15) To each there own is my philosophy. However, with multiple arguments, I might prefer def f(x): return 2.0*pi * d(x)* v(x) * sin(a(x)) flow = integrate(f, xBeg, xEnd) def g(x): return y2+ lp*(x-x2) -wallFunc( x )[0] root = findRoot(xBeg, xEnd, g, tolerance=1.0E-15) even if I might use lambda initially. (And the above is in no way a 'mess'.) In any case, as soon as one wants to do even two things with a function -- plot and integrate, or integrate with two methods and compare, or ditto with findRoot, or calculate g(root) after findRoot, one will want a separate def statement. Terry J. Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: Cool object trick
Bengt Richter wrote: > >>> m = object() > >>> m.title = 'not so fast ;-)' > Traceback (most recent call last): > File "", line 1, in ? > AttributeError: 'object' object has no attribute 'title' >>> m = object() >>> m.title = 'yeah, that's stupid' Traceback (most recent call last): File "", line 1, in ? AttributeError: 'object' object has no attribute 'title' >>> class m: pass >>> m.title = 'this works better' >>> class result: pass >>> m = result() >>> m.title = 'this also works, and is a bit less obscure' -- http://mail.python.org/mailman/listinfo/python-list
Re: better lambda support in the future?
Terry Reedy wrote:
To avoid the redundancy of 'a' and '_a', etc, how about (untested):
def dispvia(f):
dispatch[f.__name__.split('_')[1]] = f
return f
A similar idea:
Py> class DispatchTable(dict):
... def __init__(self, prefix=""):
... self._prefix = prefix
... self._ignored = len(prefix)
... def registerAs(self, name):
... def _ (f):
... self[name] = f
... return f
... return _
... def register(self, f):
... name = f.__name__
... _ignored = self._ignored
... if name[:_ignored] == self._prefix:
... name = name[_ignored:]
... self[name] = f
... return f
...
Py> dispatcher = DispatchTable("handle_")
Py> @dispatcher.register
... def handle_a(): pass
...
Py> @dispatcher.register
... def b(): pass
...
Py> @dispatcher.registerAs("c")
... def f(): pass
...
Py> for t in sorted(dispatcher.items()): print '%5s: %r'%t
...
a:
b:
c:
--
Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia
---
http://boredomandlaziness.skystorm.net
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Re: Why are tuples immutable?
"Nick Coghlan" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Although, it looks like new-style classes currently don't apply this
> rule - you get the default hash implementation from object no matter
> what:
>
> Py> class NotHashable(object):
> ... def __cmp__(self, other):
> ... return 0
> ...
> Py> hash(NotHashable())
> 10297264
> Py> d = {NotHashable(): "Hi"}
> Py> d
> {<__main__.NotHashable object at 0x009D1FF0>: 'Hi'}
>
> That may be a bug rather than a feature :)
It does seem to conflict with the doc you quoted elsewhere in this thread:
http://www.python.org/dev/doc/devel/ref/customization.html
3.3.1 Basic customization
__hash__:
if it defines __cmp__() or __eq__() but not __hash__(), its instances will
not be usable as dictionary keys.
Assuming your test is with 2.4, I'd submit a bug report noting the
discrepancy.
Terry J. Reedy
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Re: better lambda support in the future?
On 2004-12-18, Terry Reedy <[EMAIL PROTECTED]> wrote: > > "Dima Dorfman" <[EMAIL PROTECTED]> wrote in message > news:[EMAIL PROTECTED] >> Both languages compile all three functions (f and the two versions of >> g) once and choose which g to return at run-time. > > *If* OCaml or any other 'other' language compiles the two versions of g to > the final and complete functions that get returned (but I don't know if > that is so for OCaml or and other appropriate 'other'), then it does > something different from and less flexible than Python. Sorry, I glossed over the details to convey the general idea. In OCaml, as in Python, the code is compiled once but the closure is made at run-time. # f 3 == f 3;; - : bool = false where "==" is the physical equality operator like Python's "is". -- http://mail.python.org/mailman/listinfo/python-list
Re: better lambda support in the future?
On Sat, 18 Dec 2004 03:05:08 -0500, "Terry Reedy" <[EMAIL PROTECTED]> wrote:
>
>"Bengt Richter" <[EMAIL PROTECTED]> wrote in message
>news:[EMAIL PROTECTED]
>> Looks like your standard pattern could be updated:
>>
>> >>> dispatch = {}
>> >>>
>> >>> def dispvia(name):
>> ... def _(f, name=name):
>> ... dispatch[name] = f
>> ... return f
>> ... return _
>> ...
>> >>> @dispvia('a')
>> ... def handle_a(): pass
>> ...
>> >>> @dispvia('b')
>> ... def handle_b(): pass
>> ...
>> >>> @dispvia('c')
>> ... def handle_c(): pass
>> ...
>> >>> for t in sorted(dispatch.items()): print '%5s: %r'%t
>> ...
>> a:
>> b:
>> c:
>
>To avoid the redundancy of 'a' and '_a', etc, how about (untested):
>
>def dispvia(f):
> dispatch[f.__name__.split('_')[1]] = f
> return f
>
>? (Don't have 2.4 loaded yet)
That should work. Didn't want to retype ;-) I just wanted to get
to the experiment following -- did you notice that it takes the assignment
name from each "def dispatch ...", but it is actually re-assigning the returned
dispatch
*dict* as the value, not a modified function? So no function was bound to any
local name at
any time. Kind of faking the lambda thing, and allowing non-identifier keys if
desired. E.g.,
>>> dispatch = {}
>>> def dispvia(name):
... def _(f, name=name):
... f.__name__ = repr(repr(name))
... dispatch[name] = f
... return dispatch
... return _
...
>>> for k in xrange(3):
... @dispvia(k)
... def dispatch(key=k): return key
...
>>> for t in sorted(dispatch.items()): print '%5r: %r' % t
...
0:
1:
2:
>>> for t in sorted(dispatch.items()): print '%r() => %r' % (t[1], t[1]())
...
() => 0
() => 1
() => 2
Sort of the effect of
>>> dispatch2 = dict((k,lambda key=k:key) for k in xrange(3))
>>> for t in sorted(dispatch2.items()): print '%20r:%r'%t
...
0: at 0x02EE8FB4>
1: at 0x02EF402C>
2: at 0x02EF409C>
Oops, well it's not so pretty if you want to rename the lambdas in the same
expression:
>>> dispatch2 = dict((k, setattr(f, '__name__', repr(repr(k)))or f) for k,f in
>>> ((k,lambda key=k:key) for k in xrange(3)))
>>> for t in sorted(dispatch2.items()): print '%20r:%r'%t
...
0:
1:
2:
>>> for t in sorted(dispatch.items()): print '%r() => %r' % (t[1], t[1]())
...
() => 0
() => 1
() => 2
;-/
Regards,
Bengt Richter
--
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problem to compile a win32 module with Python2.4
I've a module written in C and the associated setup.py. Work fine (and compile fine with mvc) with Python 2.3.x Now I've installed Python 2.4 (all the rest unchanged) When I try to compile it, I've got a message saying that .NET SDK must be installed. Am I the only one having this problem (not found by looking for in Google) ? Is this link to Python 2.4 or my own config ? Thanks. -- http://mail.python.org/mailman/listinfo/python-list
Re: problem to compile a win32 module with Python2.4
"vincent delft" wrote: > I've a module written in C and the associated setup.py. > Work fine (and compile fine with mvc) with Python 2.3.x > > Now I've installed Python 2.4 (all the rest unchanged) > When I try to compile it, I've got a message saying that .NET SDK must be > installed. the message means what it says. > Am I the only one having this problem (not found by looking for in Google) ? Python NET SDK returns over 200,000 hits, and another 1660 hits in google groups; I didn't look at them all, but most of the hits on the first few pages are related to this issue. (googling for relevant parts of the exact error message can also be helpful...) > Is this link to Python 2.4 or my own config ? to build extensions to Python, you need to use a compiler compatible with the compiler used to build the Python core. as of Python 2.4, the core team has switched from MSVC 6.0 to MSVC 7.1 (aka Visual Studio .NET 2003). if you don't have the commercial version, you can use the free Microsoft Visual C++ Toolkit: http://groups-beta.google.com/group/comp.lang.python/msg/82e240fe42381e78 http://www.vrplumber.com/programming/mstoolkit/ or MinGW: http://jove.prohosting.com/iwave/ipython/pyMinGW.html -- http://mail.python.org/mailman/listinfo/python-list
Re: Troubleshooting: re.finditer() creates object even when no match found
Nick Coghlan wrote: Nick Coghlan wrote: Chris Lasher wrote: Hello, I really like the finditer() method of the re module. I'm having difficulty at the moment, however, because finditer() still creates a callable-iterator oject, even when no match is found. This is undesirable in cases where I would like to circumvent execution of code meant to parse out data from my finditer() object. Take a look at itertools.tee Bleh - I hit send instead of delete. Tee probably doesn't do what you want. Steve's cookbook recipe is likely a better option. Actually, there's an equally valid solution with tee too -- check Peter Otten's comments at the bottom of the recipe. Steve -- http://mail.python.org/mailman/listinfo/python-list
Re: expression form of one-to-many dict?
Fredrik Lundh wrote: Steven Bethard wrote: The map form, in this case, parses instantly in my brain, while the listcomp certainly takes a few cycles. And note that I'm not talking about the typing conciseness, but about the effort for my brain. But maybe I'm just wired funny :) Well, different at least. I find the map one harder to parse mentally. if you have trouble parsing a function call, I'm glad I don't have to maintain your Python programs... I don't know what I said to upset you so, but I do apologize. If you could tell me what it was about my statement (that I find a list comprehension to be a clearer description of program flow than a map application[1]) that so insulted you, I would be glad to avoid such comments in the future, if it would avoid such vicious replies from you. Steve [1] In my mind, the program flow is spelled out explicitly in the list comprehension and only implicitly in the map application. Thus the list comprehension is clearer to me. -- http://mail.python.org/mailman/listinfo/python-list
Re: setup.py - just what is it for ?
OK thanks for the idea. I have tried this with rather strange restults.
First, in order to be sure I knew what was going on, I wrote a script,
SpawnvTestTarget0.py, which didn't do much apart from write to a file.
I then wrote another script which spawnv'd SpawnvTestTarget0.py from
within the CGI context.
This all worked fine. At this point I thought things were looking
pretty good.
I then added in a spawnv to the setup.py (ie the script I really wanted
to be able to run) but as soon as I tried that I got an 'Internal
Server Error' message.
I've also noticed that in the directions for installing it *does* say
that you should run setup.py as root which is probably at least
contributing to the problem. Anyway out of interest here is my script
...
#!/usr/bin/python2.2
"""
A script to try to run an install.py
on a webserver to which I do not have
shell access
Usage: /installshell.cgi
"""
import cgitb; cgitb.enable()
import sys, os, cgi, pickle
from Cookie import SimpleCookie
def print_headers(headers):
for k, v in headers.items():
sys.stdout.write('%s: %s\n' % (k, v))
sys.stdout.write('\n')
print_headers({'Content-type':'text/html'})
sys.stdout.write('')
sys.stdout.write('About to execute SPAWNV Command - 1')
os.spawnv(os.P_WAIT,'/usr/bin/python2.2',['python','setup.py','install'])
os.spawnv(os.P_WAIT,'/usr/bin/python2.2',['python','SpawnvTestTarget0.py','install'])
sys.stdout.write('Finished in execute of SPAWNV Command')
sys.stdout.write('')
... I've got to go to bed now but later I'm going to try just using the
script as it is - I strongly suspect the setup.py in this case is icing
rather than cake ... then again I may be demonstrating my ignorance !
thanks for your help
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Re: Is this a good use for lambda
Charlie Taylor wrote: flow = integrate(lambda x: 2.0*pi * d(x)* v(x) * sin(a(x)),xBeg, xEnd) def _flow_func(x): return 2.0 * pi * d(x) * v(x) * sin(a(x)) flow = integrate(_flow_func, xBeg, xEnd) root = findRoot(xBeg, xEnd, lambda x: y2+ lp*(x-x2) -wallFunc( x )[0], tolerance=1.0E-15) def _root_func(x): return y2 + lp*(x - x2) - wallFunc(x)[0] root = findRoot(xBeg, xEnd, _root_func, tolerance=1.0e-15) I think those are much easier to follow. I find consistent punctuation spacing helps readability too... -- Michael Hoffman -- http://mail.python.org/mailman/listinfo/python-list
Re: Troubleshooting: re.finditer() creates object even when no match found
Steven Bethard wrote: first, iterable = peek(iterable) I really like this as a general solution to a problem that bothers me occasionally. IMHO it's much better than having UndoFiles or similar things lying about for every use case. Thanks! -- Michael Hoffman -- http://mail.python.org/mailman/listinfo/python-list
Re: PyCrust: What am I suppose to do?
It's me wrote: I am trying out PyCrust and at a lost what to do next. With the previous IDE I tried, the IDE pops up the console and the editor. From the editor, I can set up breakpoints and debug and so forth. Yes, I can even run the script. With PyCrust, the nice looking 3-pane window pops up with lots of tabs...a prompt...and then??? Where is the file I am trying to run? Even the File options are all greyed out... You can try PyAlaMode instead. Along with PyCrust, PyShell, and PyAlaCarte, it is part of the Py package of wxPython. PyAlaMode allows you to edit and save files. It is especially nice for trying some code in the interpreter, then copying that code and pasting into the editor window without pasting the prompts. --Jim -- http://mail.python.org/mailman/listinfo/python-list
Re: BASIC vs Python
On Sat, 18 Dec 2004 08:41:46 +0100, Gregor Horvath <[EMAIL PROTECTED]> wrote: > That means that you can set a breakpoint. While the debugger stops you > can edit the sourcecode (to some extent) without stopping program > execution and let the interpreter run this new code without restarting > the program. You can do that in C/C++ in some environments (within limits). About 11 years ago I used a C++ IDE called ObjectCenter which included a C/C++ interpreter and ran on my Sun workstation. It was pretty cool for the time and worked quite happily on my 350Kloc C program... If C can do it I'm sure it must be feasible in python! Alan G. Author of the Learn to Program website http://www.freenetpages.co.uk/hp/alan.gauld -- http://mail.python.org/mailman/listinfo/python-list
Re: BASIC vs Python
Gregor Horvath wrote:
> Or make any given standard python object accessible from MS Excel in 2
> minutes.
from win32com.client import Dispatch
xlApp = Dispatch("Excel.Application")
xlApp.Visible = 1
xlApp.Workbooks.Add()
xlApp.ActiveSheet.Cells(1,1).Value = 'Python Rules!'
xlApp.ActiveWorkbook.ActiveSheet.Cells(1,2).Value = 'Python Rules 2!'
xlApp.ActiveWorkbook.Close(SaveChanges=0)
xlApp.Quit()
del xlApp
(stolen from )
--
Michael Hoffman
--
http://mail.python.org/mailman/listinfo/python-list
Re: Why are tuples immutable?
Nick Coghlan <[EMAIL PROTECTED]> wrote: [quoting from the Reference Manual] > If a class defines mutable objects and implements a __cmp__() > or __eq__() method, it should not implement __hash__(), since the dictionary > implementation requires that a key's hash value is immutable (if the object's > hash value changes, it will be in the wrong hash bucket)." I know that's what it says, but I don't think it's good advice. All that is really required is that __hash__() always returns the same value over the lifetime of the object, and that objects which __cmp__() the same always return the same hash value. That's it. That's all a dictionary cares about. Making the object immutable is certainly the easiest way to achieve that goal, but it's not the only way. -- http://mail.python.org/mailman/listinfo/python-list
Re: BASIC vs Python
Michael Hoffman wrote:
Gregor Horvath wrote:
> Or make any given standard python object accessible from MS Excel in 2
> minutes.
from win32com.client import Dispatch
xlApp = Dispatch("Excel.Application")
xlApp.Visible = 1
xlApp.Workbooks.Add()
xlApp.ActiveSheet.Cells(1,1).Value = 'Python Rules!'
xlApp.ActiveWorkbook.ActiveSheet.Cells(1,2).Value = 'Python Rules 2!'
xlApp.ActiveWorkbook.Close(SaveChanges=0)
xlApp.Quit()
del xlApp
(stolen from )
Nice, but not really what the OP asked for. You make Excel accessible
from Python, instead of the other way round.
Regards,
Jan
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DNS.DiscoverNameServer query
Hi Michael where can I get the DNS packag for Python - I haven't been able to find it so far. Thanks a lot and best regards. Herbert -- http://mail.python.org/mailman/listinfo/python-list
Maven like tool?
Hi, I'm new to Python and looking to run a large project that would need automated builds and project reports such as unit test coverage. Maven is a great Java software to do this - but is there something I should use for Python? I did some searching on SF and this list but can't figure out what tools are used by teams to manage large Python projects (other than the obvious CVS). One idea is to create Maven plugins and reports that would work for Python. The plugin would offer build/test/pydoc. One report could be based on PyLint. Sounds like fun but I don't want to re-invent the wheel if something is already out there then I'd rather be a user for this one than the developer. Thanks in advance. Byron Saltysiak -- http://mail.python.org/mailman/listinfo/python-list
Re: DNS.DiscoverNameServer query
> Hi Michael eh? > where can I get the DNS packag for Python - I haven't been able > to find it so far. googling for "python dns" brings up links to: http://www.digitallumber.com/oak (server) http://sourceforge.net/projects/pydns/ (client library) among the first few hits -- but those are packages for the Domain Name System, of course. maybe you were looking for something else? -- http://mail.python.org/mailman/listinfo/python-list
Re: DNS.DiscoverNameServer query
Fredrik Lundh wrote: Hi Michael eh? where can I get the DNS packag for Python - I haven't been able to find it so far. googling for "python dns" brings up links to: http://www.digitallumber.com/oak (server) http://sourceforge.net/projects/pydns/ (client library) among the first few hits -- but those are packages for the Domain Name System, of course. maybe you were looking for something else? My favorite is http://www.dnspython.org/, which is much more usable than others I've come across. For some reason, in the past it was quite hard to find with Google. Was this what you were looking for? regards Steve -- Steve Holden http://www.holdenweb.com/ Python Web Programming http://pydish.holdenweb.com/ Holden Web LLC +1 703 861 4237 +1 800 494 3119 -- http://mail.python.org/mailman/listinfo/python-list
Re: better lambda support in the future?
Terry Reedy wrote: "Jp Calderone" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] On Fri, 17 Dec 2004 18:16:08 -0500, Terry Reedy <[EMAIL PROTECTED]> wrote: . For one-off uses not eligible for lambda treatment, where you really do not care about the name, use the same name, such as 'f', over and over, or a series such as f1, f2, ,,, or f,g,h. I have done all three in interactive explorations. Terry J. Reedy I disagree, the existence of the name itself is information as is lack of existence. If the name is absent there is an implication that it not required. An unnecessary name is visual noise. The thing that is probably a bit stupid about lambdas (I admit to having done this) is x = lambda a,b,c:... which could just as well be written def x(a,b,c):return . with only a few extra characters. -- Robin Becker -- http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
Mike Meyer wrote: PEP: XXX Title: A rational number module for Python I think it is a good idea to have rationals as part of the standard distribution but why not base this on the gmpy module (https://sourceforge.net/projects/gmpy)? That module already provides good performance. However, it does a few things that may not be good ideas. 1. Floats are converted to rationals. I think your proposal of rational to float is better. 2. Fails with a TypeError when used with a complex. Again Your proposal provides a better solution. 3. Fractional powers fail with a ValueError if the root is not exact. You do not address this in your proposal. Could silently convert to float in this case but is it better to force the user to be explicit and use the float() operation? Ray Buvel -- http://mail.python.org/mailman/listinfo/python-list
Re: os.walk bug?
Adam DePrince <[EMAIL PROTECTED]> wrote: > Each iteration of os.walk returns three parameters; one of those, dirs, > is a list of directories within the current directory pointed at by > root. Yes, it does. > Am I correct to assume that you beleve that by changing the contents of > dir you will affect how os.walk traverses the directories. If so, that > is your problem. It's not a problem: it's a correct description of os.walk behavior. > When looping in a for loop, it is generally good programming practice to > assume that nothing you do within your loop will affect which > root,dir,files tuples have been set aside to loop over. It is likely > that once os.walk was called, the items to be iterated over are > predestined (i.e. assume you are iterating over a tuple.) "Likely"? I think it's generally good programming practice to read the docs. help(os.walk) says: When topdown is true, the caller can modify the dirnames list in-place (e.g., via del or slice assignment), and walk will only recurse into the subdirectories whose names remain in dirnames; this can be used to prune the search, or to impose a specific order of visiting. Modifying and topdown is true by default. The problem was just that the poster was not using the right way to "modify the dirnames list in-place", as he was looping on said list rather than a copy and yet modifying what he was looping on (two suggestions i saw were "loop on a copy", once obtained with the odd but popular Python idiom somelist[:], once with the much more readable approach list(somelist)...). The best alternative is often to use a list comprehension, with somelist[:] on the left of the assignment since you do need to modify in-place. I.e., say that, generically speaking, you're trying (and failing) to do: for item in alist: if isnasty(item): alist.remove(item) changing the header to ``in alist[:]:'' or ``in list(alist):'' probably makes this code work, but it still can't make it GOOD... good would be: alist[:] = [item for item in alist if not isnasty(item)] Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: BASIC vs Python
"Jan Dries" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Michael Hoffman wrote:
> > Gregor Horvath wrote:
> >
> > > Or make any given standard python object accessible from MS Excel in
2
> > > minutes.
> >
> > from win32com.client import Dispatch
> >
> > xlApp = Dispatch("Excel.Application")
> > xlApp.Visible = 1
> > xlApp.Workbooks.Add()
> > xlApp.ActiveSheet.Cells(1,1).Value = 'Python Rules!'
> > xlApp.ActiveWorkbook.ActiveSheet.Cells(1,2).Value = 'Python Rules 2!'
> > xlApp.ActiveWorkbook.Close(SaveChanges=0)
> > xlApp.Quit()
> > del xlApp
> >
> > (stolen from )
>
> Nice, but not really what the OP asked for.
What the OP asked for isn't what was discussed neither.
> You make Excel accessible
> from Python, instead of the other way round.
>
Again, that's a political issue - not technical nor language related.
Monopolictic empire has their way of doing things and as IT slaves, we have
to obey what the master BG wants us to do.
Anyway, here's another piece I find very nice:
http://starship.python.net/crew/pirx/spam7/COMtut.PPT
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Re: Maven like tool?
"Byron Saltysiak" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] Hi, I'm new to Python and looking to run a large project that would need automated builds and project reports such as unit test coverage. Maven is a great Java software to do this - but is there something I should use for Python? I did some searching on SF and this list but can't figure out what tools are used by teams to manage large Python projects (other than the obvious CVS). One idea is to create Maven plugins and reports that would work for Python. The plugin would offer build/test/pydoc. One report could be based on PyLint. Sounds like fun but I don't want to re-invent the wheel if something is already out there then I'd rather be a user for this one than the developer. Thanks in advance. Byron Saltysiak Have you looked at SCons? http://www.scons.org/ The approach seems quite interesting and has the potential to avoid having to learn several different languages in order to do builds, as well as the possibility to scale well. Martin Fowler has this to say on the subject: http://martinfowler.com/bliki/BuildLanguage.html Besides, it's in pure Python. John Roth -- http://mail.python.org/mailman/listinfo/python-list
RE: Cool object trick
Bengt Richter wrote:
> >>> m=type('',(),{})()
> >>> m.title = 'not so fast ;-)'
> >>> m.title
> 'not so fast ;-)'
Now THAT is a cool object trick. :)
FuManChu
--
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Re: A rational proposal
"Mike Meyer" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] PEP: XXX Title: A rational number module for Python Version: $Revision: 1.4 $ Last-Modified: $Date: 2003/09/22 04:51:50 $ Author: Mike Meyer <[EMAIL PROTECTED]> Status: Draft Type: Staqndards Content-Type: text/x-rst Created: 16-Dec-2004 Python-Version: 2.5 Post-History: 30-Aug-2002 Abstract This PEP proposes a rational number module to add to the Python standard library. [snip] The ``Rational`` class shall define all the standard mathematical operations: addition, subtraction, multiplication, division, modulo and power. It will also provide the methods: - max(*args): return the largest of a list of numbers and self. - min(*args): return the smallest of a list of numbers and self. max() and min() are already part of the standard library. Providing them as instance methods is quite irregular. - decimal(): return the decimal approximation to the rational in the current context. This ought to be the responsibility of the decimal() constructor. I can see including it here to avoid adding it to the decimal() constructor, but IMO it's bad design. - inv(): Return the inverse of self. I presume this means that if the rational is x/y, then it returns y/x? Rationals will mix with all other numeric types. When combined with an integer type, that integer will be converted to a rational before the operation. When combined with a floating type - either complex or float - the rational will be converted to a floating approximation before the operation, and a float or complex will be returned. The reason for this is that floating point numbers - including complex - are already imprecise. To convert them to rational would give an incorrect impression that the results of the operation are precise. Decimals will be converted to rationals before the operation. [Open question: is this the right thing to do?] I'd prefer to have rationals converted to decimals before the operation, for the same reason that they're converted to floats. Decimals also have limited precision. Rationals can be converted to floats by float(rational), and to integers by int(rational). If this is the case, then there is no reason to have a separate member operation to convert rationals to decimal. Consistency says to do it the same way for all similar operations. ... John Roth -- http://mail.python.org/mailman/listinfo/python-list
Re: BASIC vs Python
Does this one count?
http://hacks.oreilly.com/pub/h/2630
"Jan Dries" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> Michael Hoffman wrote:
> > Gregor Horvath wrote:
> >
> > > Or make any given standard python object accessible from MS Excel in
2
> > > minutes.
> >
> > from win32com.client import Dispatch
> >
> > xlApp = Dispatch("Excel.Application")
> > xlApp.Visible = 1
> > xlApp.Workbooks.Add()
> > xlApp.ActiveSheet.Cells(1,1).Value = 'Python Rules!'
> > xlApp.ActiveWorkbook.ActiveSheet.Cells(1,2).Value = 'Python Rules 2!'
> > xlApp.ActiveWorkbook.Close(SaveChanges=0)
> > xlApp.Quit()
> > del xlApp
> >
> > (stolen from )
>
> Nice, but not really what the OP asked for. You make Excel accessible
> from Python, instead of the other way round.
>
> Regards,
> Jan
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Re: A rational proposal
"Raymond L. Buvel" <[EMAIL PROTECTED]> writes: > Mike Meyer wrote: >> PEP: XXX >> Title: A rational number module for Python > > > I think it is a good idea to have rationals as part of the standard > distribution but why not base this on the gmpy module > (https://sourceforge.net/projects/gmpy)? That module already provides > good performance. However, it does a few things that may not be good > ideas. It wraps a third party package, which can't really be added to the standard libraray. The documentation for a rationa number package in Python should include a pointer to gmpy with a note about performance. > 3. Fractional powers fail with a ValueError if the root is not > exact. You do not address this in your proposal. Could silently > convert to float in this case but is it better to force the user to be > explicit and use the float() operation? You're right. Raising a rational to a rational power isn't covered, and may produce an irrational answer. Raising a rational to a floating point power will cause the rational to be converted to a float, as is specified. I think forcing the use of float is wrong, as the rational may be an integer. I'm not sure what should be done, so this is being added as an open issue. Thanks, http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
"John Roth" <[EMAIL PROTECTED]> writes: > "Mike Meyer" <[EMAIL PROTECTED]> wrote in message > news:[EMAIL PROTECTED] >> PEP: XXX >> Title: A rational number module for Python >> The ``Rational`` class shall define all the standard mathematical >> operations: addition, subtraction, multiplication, division, modulo >> and power. It will also provide the methods: >> >> - max(*args): return the largest of a list of numbers and self. >> - min(*args): return the smallest of a list of numbers and self. > > max() and min() are already part of the standard library. > Providing them as instance methods is quite irregular. They don't handle decimals or rationals. This is following the lead of the decimal package. >> - decimal(): return the decimal approximation to the rational in the >> current context. > > This ought to be the responsibility of the decimal() constructor. > I can see including it here to avoid adding it to the decimal() > constructor, but IMO it's bad design. Good point. Currently, objects now how to convert themselves to int, float and complex. Should Rational now how to convert itself to Decimal (and conversely, decimal now how to convert itself to Rational)? >> - inv(): Return the inverse of self. > I presume this means that if the rational is x/y, then it > returns y/x? Is this better wording: - inv(): Return self to the power -1. >> Rationals will mix with all other numeric types. When combined with an >> integer type, that integer will be converted to a rational before the >> operation. When combined with a floating type - either complex or >> float - the rational will be converted to a floating approximation >> before the operation, and a float or complex will be returned. The >> reason for this is that floating point numbers - including complex - >> are already imprecise. To convert them to rational would give an >> incorrect impression that the results of the operation are >> precise. Decimals will be converted to rationals before the >> operation. [Open question: is this the right thing to do?] > > I'd prefer to have rationals converted to decimals before > the operation, for the same reason that they're converted > to floats. Decimals also have limited precision. I'm of two minds about this one. One is that decimals have limited precision. But they represent their values exactly, whereas 1E73 isn't a 1 followed by 73 zeros when converted to an int. On the other hand, every decimal has a rational equivalent, but not vice versa. Thanks, http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
example code sought
There's something quite simple I'd like to do, but I'm hampered by lack of knowledge regarding Tkinter. If someone could help me out with a snippet of maximally-simple code showing, in general terms, how to do this, that would be really great. What I want to do is simply to move a shape around on the screen using the mouse. I've looked at Tkdnd.py but I can't seem to extract what I need from the more involved stuff in there. Peace, STM -- http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
On Sat, 18 Dec 2004 12:29:10 -0600, Mike Meyer <[EMAIL PROTECTED]> wrote: >"Raymond L. Buvel" <[EMAIL PROTECTED]> writes: > > > Mike Meyer wrote: > >> PEP: XXX > >> Title: A rational number module for Python > > > > > > I think it is a good idea to have rationals as part of the standard > > distribution but why not base this on the gmpy module > > (https://sourceforge.net/projects/gmpy)? That module already provides > > good performance. However, it does a few things that may not be good > > ideas. > > It wraps a third party package, which can't really be added to the > standard libraray. The documentation for a rationa number package in > Python should include a pointer to gmpy with a note about performance. > This is not true. As evidence, see the following modules: readline _ssl _tkinter _curses, _curses_panel dbm, gdbm, _bsddb zlib pyexpat Not to mention the crazy, mega-platform specific modules like gl, nis, fm, sgi, and more. Nor Python's tight dependency on another third party library, libc. ;) Note I am not advocating the use of gmpy (nor the avoidance of it), simply pointing out that there is ample precedent in the standard library for dependence on third party libraries. Jp -- http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
On Sat, 18 Dec 2004 12:40:04 -0600, Mike Meyer <[EMAIL PROTECTED]> wrote: >"John Roth" <[EMAIL PROTECTED]> writes: > > > "Mike Meyer" <[EMAIL PROTECTED]> wrote in message > > news:[EMAIL PROTECTED] > >> PEP: XXX > >> Title: A rational number module for Python > >> The ``Rational`` class shall define all the standard mathematical > >> operations: addition, subtraction, multiplication, division, modulo > >> and power. It will also provide the methods: > >> > >> - max(*args): return the largest of a list of numbers and self. > >> - min(*args): return the smallest of a list of numbers and self. > > > > max() and min() are already part of the standard library. > > Providing them as instance methods is quite irregular. > > They don't handle decimals or rationals. This is following the lead of > the decimal package. They do handle decimals. They handle any object which define __cmp__, or the appropriate rich comparison methods. The Decimal type seems to define min and max so that NaNs can be treated specially, but I glean this understanding from only a moment of reading decimal.py. Perhaps someone more well informed can declare definitively the purpose of these methods. Also, note that the signatures are not Decimal.max(*args) and Decimal.min(*args), but rather each takes a single decimal argument in addition to self and an optional context argument. So if the goal is symmetry with the Decimal type, then Rational.max() and Rational.min() should take only one argument. Jp -- http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
[Jp Calderone] ... > The Decimal type seems to define min and max so that NaNs > can be treated specially, but I glean this understanding from only > a moment of reading decimal.py. Perhaps someone more well > informed can declare definitively the purpose of these methods. To conform to the semantics of the min and max operations defined in IBM's proposed standard for decimal arithmetic: http://www2.hursley.ibm.com/decimal/ and in particular: http://www2.hursley.ibm.com/decimal/daops.html#refmax and http://www2.hursley.ibm.com/decimal/daops.html#refmin Note that this is a moving target. -- http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
Jp Calderone <[EMAIL PROTECTED]> writes: > They do handle decimals. They handle any object which define __cmp__, > or the appropriate rich comparison methods. That settles that. They're gone from the proposal. So is the method inverse, as that's simply 1/rational. http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
"Mike Meyer" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] >>> Title: A rational number module for Python >> 1. I would call this Not Necessary but Nice. Perhaps the time has come to include rationals in the Standard Library, given that its expansion will be a focus of the 2.5 cycle. It certainly seems time to have such a PEP pushed to a formal decision. To increase the chance of getting BDFL approval, you might search clp and especially pydev archives for Guido's (and maybe other developers') past objections and prepare to meet them. I vaguely remember things like too specialized and not needed enough, need already met by third party modules, and the inherent clumbsiness of exact rational calculations (due to length growth of 'ators and the time needed to remove common factors, if one does). 2. The initial and debugged implementation should be in Python at least until the interface and behavioral specs are finalized. Beside the obvious reasons, this will help the PyPy project which is currently being slowed a bit by the needed to rewrite C-coded modules in Python. Terry J. Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: better lambda support in the future?
"Bengt Richter" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> On Sat, 18 Dec 2004 03:05:08 -0500, "Terry Reedy" <[EMAIL PROTECTED]>
> wrote:
>>To avoid the redundancy of 'a' and '_a', etc, how about (untested):
>>
>>def dispvia(f):
>> dispatch[f.__name__.split('_')[1]] = f
>> return f
> That should work. Didn't want to retype ;-) I just wanted to get
> to the experiment following -- did you notice that it takes the
> assignment
> name from each "def dispatch ...", but it is actually re-assigning the
> returned dispatch
> *dict* as the value, not a modified function?
Yes, I noticed that your second version of dispvia, which I snipped,
returned dispatch instead of the nested function named _. But I did not
quite think thru the import of so doing.
I think one or more of these recipies might at least be worthy of the
cookbook site so they can be easily referenced in response to future
postings.
Terry J. Reedy
--
http://mail.python.org/mailman/listinfo/python-list
ActiveState Python 2.4 Woes
I am having a lot of problems with this distribution. Is anyone else? Among many, many problems in the debugger I also see the error below when I start PythonWin using the context menu when selecting a python file in the windows shell explorer. Anyone having this problem? I done a complete uninstall/re-install but to no avail. Portions Copyright 1994-2004 Mark Hammond ([EMAIL PROTECTED]) - see 'Help/About PythonWin' for further copyright information. >>> Traceback (most recent call last): File "C:\Python24\Lib\site-packages\pythonwin\pywin\mfc\docview.py", line 91, in CreateNewFrame wnd.LoadFrame(self.GetResourceID(), -1, None, context) # triggers OnCreateClient... win32ui: LoadFrame failed win32ui: CreateNewFrame() virtual handler (>) raised an exception TypeError: PyCTemplate::CreateNewFrame must return a PyCFrameWnd object. -- http://mail.python.org/mailman/listinfo/python-list
Re: How to set condition breakpoints?
"Christopher J. Bottaro" <[EMAIL PROTECTED]> writes on Fri, 10 Dec 2004 11:45:19 -0600: > ... > Hmm, thanks for the suggestions. One more quick question. Is it even > possible to set a breakpoint in a class method in pdb.py? I can't even say > "break Class.f" without the condition. I don't think the documentation for > pdb is very good...=( What happens? I can do it... However, I had to fix "pdb" to prevent it to set the breakpoint inside the docstring (where it is not effective). I hope the fix found its way into the most recent Python versions (2.3.4 and 2.4). Dieter -- http://mail.python.org/mailman/listinfo/python-list
Re: ActiveState Python 2.4 Woes
Just installed Python 2.4 (from Python.org) and the Win32 extesions (from Mark's site) and am now having NO problems. I'll report more info as I experience it. -- http://mail.python.org/mailman/listinfo/python-list
Re: better lambda support in the future?
Jason Zheng wrote:
I'm wondering why python still has limited lambda support. What's
stopping the developers of python to support more lisp-like lambda
function?
See boo and its support for closures: http://boo.codehaus.org/
http://boo.codehaus.org/Closures
It works with "def" or "do", or single-line closures use {}.
x = def:
print "hello"
A closure with parameters:
c = def(x1 as int, x2 as string):
print x1, x2
Single line closures use {}
c = {print("hello")}
Single line with parameters
c = {item as string | print(item)}
#Passing closures to a method as a parameter:
def mymethod(c as callable):
c()
x = mymethod( {print("hello")} )
#passing a multi-line closure as a parameter:
x = mymethod() do():
print "hello"
#Adding a closure to an event handler:
button.Click += def ():
print("${button} was clicked!")
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Re: A beginner's problem...
Try deleting the Compiled Python File that was created during import -- extension pyc. Then import again. It seems to me (I'm a novice too) that, when you import a module, Python automatically compiles it. Then when you import it later, the compiled version is imported if it exists. "Amir Dekel" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Hello everyone, > > First, I have to say that Python is one of the coolest programing > languages I have seen. > And now for the problem (must be a silly one): > When I import a module I have wrote, and then I find bugs, it seems that > I can't import it again after a fix it. It always shows the same > problem. I try del module but it doesn't work. > (I use Python 2.4 with the ActivePython pack (PythonWin IDE) > > Solution anyone? > > Amir -- http://mail.python.org/mailman/listinfo/python-list
Re: expression form of one-to-many dict?
In respect to map(func, seq) versus [func(i) for i in seq], for pre-existing func, 'OP' wrote The map form, in this case, parses instantly in my brain, while the listcomp certainly takes a few cycles. And note that I'm not talking about the typing conciseness, but about the effort for my brain. But maybe I'm just wired funny :) >> Steven Bethard wrote: >>>Well, different at least. I find the map one harder to parse mentally. [and] > [1] In my mind, the program flow is spelled out explicitly in the list > comprehension and only implicitly in the map application. Thus the list > comprehension is clearer to me. For pre-existing func, I slightly prefer the map form because the sequential program flow is *not* spelled out. So I can more easily see the sequence items mapped in parallel. On the other hand, I probably prefer [i-expression for i in seq] to map(lambda i: i-expression, seq) because I find the (unnecessary) mental construction of a function object to be a compensating burden. I can easily imagine that others will find themselves more comfortably on one side or the other of the mental fence I find myself sitting on ;-). Terry J. Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: better lambda support in the future?
On Sat, 18 Dec 2004 14:39:54 -0500, "Terry Reedy" <[EMAIL PROTECTED]> wrote:
>
>"Bengt Richter" <[EMAIL PROTECTED]> wrote in message
>news:[EMAIL PROTECTED]
>> On Sat, 18 Dec 2004 03:05:08 -0500, "Terry Reedy" <[EMAIL PROTECTED]>
>> wrote:
>>>To avoid the redundancy of 'a' and '_a', etc, how about (untested):
>>>
>>>def dispvia(f):
>>> dispatch[f.__name__.split('_')[1]] = f
>>> return f
>
>> That should work. Didn't want to retype ;-) I just wanted to get
>> to the experiment following -- did you notice that it takes the
>> assignment
>> name from each "def dispatch ...", but it is actually re-assigning the
>> returned dispatch
>> *dict* as the value, not a modified function?
>
>Yes, I noticed that your second version of dispvia, which I snipped,
>returned dispatch instead of the nested function named _. But I did not
That's actually not the right "instead" ;-) I.e., the function _ returns
dispatch instead of the function passed to _it_ for deco-modification.
>quite think thru the import of so doing.
>
>I think one or more of these recipies might at least be worthy of the
>cookbook site so they can be easily referenced in response to future
>postings.
>
It is a little sneaky though, so it might not be prudent to promote
without a little more experimentation? I just like to explore ;-)
Regards,
Bengt Richter
--
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Re: os.walk bug?
"Alex Martelli" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > for item in alist: >if isnasty(item): >alist.remove(item) > > changing the header to ``in alist[:]:'' or ``in list(alist):'' probably > makes this code work, but it still can't make it GOOD... good would be: > > alist[:] = [item for item in alist if not isnasty(item)] Given that the OP has verified that replacing alist with list(alist) in the for statement solves his problems, I agree that the listcomp is even nicer in that it avoids the bug trap, the over-copying of the entire list, the alternative of iterating in reverse, and the n**2 behavior of multiple correct deletes from a long list. Terry J. Reedy -- http://mail.python.org/mailman/listinfo/python-list
Re: os.walk bug?
Terry Reedy <[EMAIL PROTECTED]> wrote: > "Alex Martelli" <[EMAIL PROTECTED]> wrote in message > news:[EMAIL PROTECTED] > > for item in alist: > >if isnasty(item): > >alist.remove(item) > > > > changing the header to ``in alist[:]:'' or ``in list(alist):'' probably > > makes this code work, but it still can't make it GOOD... good would be: > > > > alist[:] = [item for item in alist if not isnasty(item)] > > Given that the OP has verified that replacing alist with list(alist) in the > for statement solves his problems, ...and that of course is crucial (using list(alist) vs alist[:] is of course quite minor, just my pet peeve that some of us old Pythonistas go around doign the [:] bit as if it was obvious rather than the clearer list() call;-)... > I agree that the listcomp is even nicer > in that it avoids the bug trap, the over-copying of the entire list, the > alternative of iterating in reverse, and the n**2 behavior of multiple > correct deletes from a long list. Right, the O(N**2) is generally the biggie (copying the entire list is just O(N), and with a small multiplicative constant anyway). 2.4's ``reversed'' built-in is nice for those case in which you do need reverse iteration, of course. But list comprehensions are often even better for such tasks as "remove all items such that p(item)"... Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: Cool object trick
Robert Brewer wrote:
Bengt Richter wrote:
>>> m=type('',(),{})()
>>> m.title = 'not so fast ;-)'
>>> m.title
'not so fast ;-)'
Now THAT is a cool object trick. :)
Heh.
Look ma, Perlython!
Cheers,
Nick.
--
Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia
---
http://boredomandlaziness.skystorm.net
--
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Re: A beginner's problem...
[Format recovered from top posting.] "James Martin" <[EMAIL PROTECTED]> writes: > > > "Amir Dekel" <[EMAIL PROTECTED]> wrote in message > news:[EMAIL PROTECTED] >> Hello everyone, >> First, I have to say that Python is one of the coolest programing >> languages I have seen. >> And now for the problem (must be a silly one): >> When I import a module I have wrote, and then I find bugs, it seems that >> I can't import it again after a fix it. It always shows the same >> problem. I try del module but it doesn't work. >> (I use Python 2.4 with the ActivePython pack (PythonWin IDE) >> >> Solution anyone? > Try deleting the Compiled Python File that was created during import -- > extension pyc. Then import again. > > It seems to me (I'm a novice too) that, when you import a module, Python > automatically compiles it. Then when you import it later, the compiled > version is imported if it exists. It compares the dates on the .py file with the .pyc file, and recompiles the .py file if it's newer. Doing a second import will find the module in sys.modules and not bother looking in the file system. The solution is to reload(module) instead of import module. http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: better lambda support in the future?
Bengt Richter wrote: It is a little sneaky though, so it might not be prudent to promote without a little more experimentation? I just like to explore ;-) I don't think even the py-dev discussions of this settled on whether such tricks were "very cool" or "downright evil". They're probably less evil than sys._getframe hacks, though :) Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
Re: A beginner's problem...
Mike Meyer wrote: Doing a second import will find the module in sys.modules and not bother looking in the file system. The solution is to reload(module) instead of import module. What if I import using "from module import class"? It seems to me that I can't use reload then, or I just couldn't find the right syntax... -- http://mail.python.org/mailman/listinfo/python-list
Re: BASIC vs Python
Dennis Lee Bieber <[EMAIL PROTECTED]> writes: I like your categories, but you forgot one. > On Fri, 17 Dec 2004 13:54:45 -0500, Adam DePrince <[EMAIL PROTECTED]> > declaimed the following in comp.lang.python: >> I'd like to ask everybody a simple question. How many computer >> languages are you completely and utterly fluent in? The reason I ask is > > "Completely and utterly"? None -- they change too fast to claim > that. Nah. C is pretty much set. The standard libraries you need, on the other hand, are something else. > Productive in? Python, C, Eiffel, make > Familiar enough to at least produce code in? FORTRAN, sh, awk You forgot an important category here. Can debug, if not produce code from scratch: Common LISP, Pascal, Scheme > Have toyed with? I presume these means you've written at least one program in it, and forgotten most of the langauge since. Logo, Erlang, ML, Prolog, Postscript, Forth, Perl, yacc, lex, Amiga REXX, VMS batch scripts. > Want to forget? MS BASIC (Apple, TRS80 and Amiga), Logo, Assembly(8080, z80, 8086, 6809, 68K, PDP-11, PDP-10), Perl, C++, Java http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: A beginner's problem...
Amir Dekel <[EMAIL PROTECTED]> writes: > Mike Meyer wrote: >> Doing a second import will find the module in sys.modules and not >> bother looking in the file system. The solution is to reload(module) >> instead of import module. >> What if I import using "from module import class"? It seems to me that > I can't use reload then, or I just couldn't find the right syntax... I'm pretty sure you'll have to import the module and reload it. "from module import class" still puts the module in sys.modules, so trying to import something from it again will find it in there. http://www.mired.org/home/mwm/ Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information. -- http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
Mike Meyer wrote: max() and min() are already part of the standard library. Providing them as instance methods is quite irregular. They don't handle decimals or rationals. This is following the lead of the decimal package. As Tim pointed out - decimal has its own versions of max & min which conform to the decimal specification. For the builtin in max and min, decimal's behave like any other number. - decimal(): return the decimal approximation to the rational in the current context. This ought to be the responsibility of the decimal() constructor. I can see including it here to avoid adding it to the decimal() constructor, but IMO it's bad design. Actually, what's missing at the moment is the decimal equivalent of __int__, __float__, etc. Generally, for new types, it is the new type's responsibility to play well with pre-existing types, not the other way round (think about what the __str__ method actually does - it's the type conversion method for turning your object into a string object) Good point. Currently, objects now how to convert themselves to int, float and complex. Should Rational now how to convert itself to Decimal (and conversely, decimal now how to convert itself to Rational)? Doing either of those properly requires adding slots to the type structure (since you need new magic methods - __decimal__ and __rational__). I believe the goal is to have Decimal.decimal become a builtin for Py 2.5, in which case, I would also hope to see a __decimal__ special method. The correct answer would then be for Rational.rational to handle decimals in its constructor, and provide an implementation of __decimal__ (similar to the way Decimal.decimal interacts with the other builtin types). Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
Re: A beginner's problem...
Amir Dekel wrote: Mike Meyer wrote: Doing a second import will find the module in sys.modules and not bother looking in the file system. The solution is to reload(module) instead of import module. What if I import using "from module import class"? It seems to me that I can't use reload then, or I just couldn't find the right syntax... Correct. Using a non-from import is actually easier when experimenting, since reload is easier to use. If you have used a from-style import, you have to do this to force a reload of the relevant class: Py> from module import x Py> # Do stuff Py> import module Py> reload(module) Py> from module import x Py> # We now have the updated version of x Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
How about "pure virtual methods"?
Hello, I thought about a new Python feature. Please tell me what you think about it. Say you want to write a base class with some unimplemented methods, that subclasses must implement (or maybe even just declare an interface, with no methods implemented). Right now, you don't really have a way to do it. You can leave the methods with a "pass", or raise a NotImplementedError, but even in the best solution that I know of, there's now way to check if a subclass has implemented all the required methods without running it and testing if it works. Another problem with the existing solutions is that raising NotImplementedError usually means "This method might be implemented some time", and not "you must implement this method when you subclass me". What I suggest is a new class, called notimplemented (you may suggest a better name). It would get a function in its constructor, and would just save a reference to it. The trick is that when a new type (a subclass of the default type object) is created, It will go over all its members and check to see if any of them is a notimplemented instance. If that is the case, it would not allow an instantiation of itself. What I want is that if I have this module: == class BaseClass(object): def __init__(self): ... @notimplemented def save_data(self, filename): """This method should save the internal state of the class to a file named filename. """ pass class RealClass(BaseClass): def save_data(self, filename): open(filename).write(self.data) == then if I try to instantiate BaseClass I would get an exception, but instantiating RealClass will be ok. Well, what do you say? Noam Raphael -- http://mail.python.org/mailman/listinfo/python-list
Replace single item in tkinter ListBox
Hello, Is there a quick way to replace the content of a single item in tkinter's listbox? Currently my solution is to first delete the item, then insert a new item at the same position. I think there may be better way. Zhang Le -- http://mail.python.org/mailman/listinfo/python-list
Re: How about "pure virtual methods"?
On Sun, 19 Dec 2004 01:49:50 +0200, Noam Raphael <[EMAIL PROTECTED]> wrote:
>Hello,
>
> I thought about a new Python feature. Please tell me what you think
> about it.
>
> Say you want to write a base class with some unimplemented methods, that
> subclasses must implement (or maybe even just declare an interface, with
> no methods implemented). Right now, you don't really have a way to do
> it. You can leave the methods with a "pass", or raise a
> NotImplementedError, but even in the best solution that I know of,
> there's now way to check if a subclass has implemented all the required
> methods without running it and testing if it works.
What about the mechanism you described below? That can be implemented
without any changes to the Python language or additions to the standard
library, and does just what you want.
> Another problem with
> the existing solutions is that raising NotImplementedError usually means
> "This method might be implemented some time", and not "you must
> implement this method when you subclass me".
def foobar(x, y, z):
raise NotImplementedError("Subclasses must implement this")
>
> What I suggest is a new class, called notimplemented (you may suggest a
> better name). It would get a function in its constructor, and would just
> save a reference to it. The trick is that when a new type (a subclass of
> the default type object) is created, It will go over all its members and
> check to see if any of them is a notimplemented instance. If that is the
> case, it would not allow an instantiation of itself.
>
> What I want is that if I have this module:
>
> ==
>
> class BaseClass(object):
> def __init__(self):
> ...
>
> @notimplemented
> def save_data(self, filename):
> """This method should save the internal state of the class to
> a file named filename.
> """
> pass
>
> class RealClass(BaseClass):
> def save_data(self, filename):
> open(filename).write(self.data)
>
> ==
>
> then if I try to instantiate BaseClass I would get an exception, but
> instantiating RealClass will be ok.
>
>
> Well, what do you say?
It seems as though this is more in the realm of PyChecker and unit
tests than desirable language features. PyChecker will already point
out when a method cannot do anything but raise an exception, as a "pure
virtual function" does. Unit tests, similarly, will show you where you
forgot to implement a method, because they _will_ exercise your code.
Nothing is preventing you from creating a base class and a
notimplemented decorator which cooperative to make subclasses
uninstantiable if "pure virtual methods" remain, though.
Jp
--
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Re: How about "pure virtual methods"?
Noam Raphael wrote: Well, what do you say? Raising NotImplementedError in the methods that need to be overridden is much more customary, more straightforward, and already works fine. -- Erik Max Francis && [EMAIL PROTECTED] && http://www.alcyone.com/max/ San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis We learn from history that we do not learn from history. -- Georg Friedrich Wilhelm Hegel -- http://mail.python.org/mailman/listinfo/python-list
Plugin system; imp module head scratch
Hi, all,
I'm trying to implement a simple plugin framework, with some
unexpected results. I'm using Python 2.3.4 on Windows 2000.
My script loader.py loads plugin packages from a directory (in this
case its own), and checks a variable defined in the package's
__init__.py for information on the plugin.
The directory in which loader.py sits is itself a package::
plugin_test
|
+ Plugin1
||
|__init__.py
|
__init__.py
loader.py
I must be misunderstanding how the imp module works, or something.
Although the correct package is returned by my helper method, its
member variables are those of the the parent package, plugin_test.
The output of this demo is::
Directory plugin_test
Which seems contradictory. What have I got wrong?
Best Regards,
Dave
This is plugin_test/Plugin1/__init__.py::
dir = "plugin_test/Plugin1"
This is plugin_test/__init__.py::
dir = "plugin_test"
And here is the loader script, plugin_test/loader.py::
import os
import imp
def GetPackage(name, peerFile, relPath = '.'):
"""
Return the named Python package on a
relative path from the file given
"""
path = os.path.normpath(
os.path.join(os.path.dirname(peerFile), relPath))
try:
fObj, path, descr = imp.find_module(name, [path])
except ImportError:
return None
if descr[2] != imp.PKG_DIRECTORY:
return None
try:
return imp.load_module(name, None, '', descr)
except:
return None
if __name__ == "__main__":
pkg = GetPackage("Plugin1", __file__, '.')
print pkg
print "Directory ", pkg.dir
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Use macros in Excel via win32com
I'm creating an excel document dynamically from scratch using Python and the win32com module. All is well, but now I need to add a macro to the spreadsheet and run it (to enable some sorting features in the spreadsheet). I think I know how to run a macro once it's installed (using the Run method of the excel application object...I think), but I can't figure out how to "install" the VBA macro code into the spreadsheet to begin with from my Python script. Any tips appreciated. Thanks, Chris -- http://mail.python.org/mailman/listinfo/python-list
Easy "here documents" ??
I've done some Googling around on this and it seems like creating a here document is a bit tricky with Python. Trivial via triple-quoted strings if there's no need for variable interpolation but requiring a long, long formatted arglist via (%s,%s,%s,ad infinitum) if there is. So my question is: Is there a way to produce a very long multiline string of output with variables' values inserted without having to resort to this wacky """v = %s"""%(variable) business? Thanks, Jim, Python no0b -- "I regard NASCAR the same way I regard gay porn: I know it exists and I know some guys like it; I just don't want to see it." -- Z. B. Goode -- http://mail.python.org/mailman/listinfo/python-list
How do I define the search path for personal library
Dear all, i have a simple question. Suppose I have my classes such as myClass1.py myClass2.py etc which I keep in a special folder ~/py_libs Now suppose I have a program that is not in py_libs but I want to do import myClass1 # note: myClass1 is not in the current directory how can I set the search path for python so that it can find myClass1? thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: Use macros in Excel via win32com
"chris" <[EMAIL PROTECTED]> wrote: >I'm creating an excel document dynamically from scratch using Python >and the win32com module. All is well, but now I need to add a macro to >the spreadsheet and run it (to enable some sorting features in the >spreadsheet). I think I know how to run a macro once it's installed >(using the Run method of the excel application object...I think), but I >can't figure out how to "install" the VBA macro code into the >spreadsheet to begin with from my Python script. >Any tips appreciated. Here is a manual solution for Excel 2003. At the bottom of the spreadsheet, right-click on one of the tabs (default names sheet1 sheet2 sheet3). Click "view code" on the menu, which should bring up a Microsoft Visual Basic editor. Select Module from the Insert menu at the top, and paste the VBA code there. == Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet News== http://www.newsfeeds.com The #1 Newsgroup Service in the World! >100,000 Newsgroups ---= 19 East/West-Coast Specialized Servers - Total Privacy via Encryption =--- -- http://mail.python.org/mailman/listinfo/python-list
Re: How about "pure virtual methods"?
Noam Raphael <[EMAIL PROTECTED]> wrote:
> What I want is that if I have this module:
>
> ==
>
> class BaseClass(object):
> def __init__(self):
> ...
>
> @notimplemented
> def save_data(self, filename):
> """This method should save the internal state of the class to
> a file named filename.
> """
> pass
>
> class RealClass(BaseClass):
> def save_data(self, filename):
> open(filename).write(self.data)
>
> ==
>
> then if I try to instantiate BaseClass I would get an exception, but
> instantiating RealClass will be ok.
>
>
> Well, what do you say?
It's already easy to do as long as you don't insist that BaseClass must
subclass object (or allow a __metaclass__ assignment there). Basically,
what you describe is the job of a custom metaclass, because that's where
the __call__ method on classes is defined (classes being instances of
the metaclass)... much cleaner than tampering with the __new__ or
__init__ at class level.
At sketch level, you'd have, say:
def notimplemented(f):
# save some data about f somewhere if you wish, then, e.g.:
return notimplemented
import inspect
class Meta_for_NR(type):
def __init__(cls, cn, cb, cd):
super(Meta_for_NR, cls).__init__(cn, cb, cd)
abstract_methods = []
for n, v in inspect.getmembers(cls, inspect.ismethod):
if v is notimplemented: abstract_methods.append(n)
cls._abstract_methods = abstract_methods
def __call__(cls, *a, **k):
if cls._abstract_methods:
raise TypeError, ("Cannot instantiate abstract class %s."
" Abstract methods: %s." % (cls.__name__,
', '.join(cls._abstract_methods)))
return super(Meta_for_NR, cls).__call__(*a, **k)
class Base_for_NR: __metaclass__ = Meta_for_NR
Inheriting from Base_for_NR instead of inheriting from object should
give you just the behavior you desire (net of the fact that this code of
mine is untested, just a sketch -- but the key ideas shd be ok).
If you can implement this and get it into wide usage, it may well be
adopted in the standard library. Unless there is proof by experience
that a lot of people like this approach better than the de facto
standard, such adoption is very unlikely. But the great thing is that
it's EASY to implement your ideas and try to garner a following for
them, so you stand a chance to get them into the standard library if you
can prove they really work well and are well-liked!
Alex
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Re: BASIC vs Python
On Fri, 17 Dec 2004 20:41:11 -0600, Mike Meyer <[EMAIL PROTECTED]> wrote: >Scott Robinson <[EMAIL PROTECTED]> writes: > >> Forth seems better than basic, but is *weird* (I tried it for a >> while). I'm not sure going from Forth to C (or Python) would be much >> easier than Basic to C or Python. The biggest disappointment for >> Forth was that no significant Forth chips were made (and none until it >> was too late). A machine designed to be run on Forth would have been >> unbelievably powerful from the late 70s to the mid 90s (it would be >> more painful now than the x86 legacy, but still). > >I think you overestimate how long the Forth chip would have been a >serious competitor to x`the x86 line. LISP chips - which should have >all the same advantages - didn't last that long. > >http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
Raymond L. Buvel <[EMAIL PROTECTED]> wrote: > Mike Meyer wrote: > > PEP: XXX > > Title: A rational number module for Python > > > I think it is a good idea to have rationals as part of the standard > distribution but why not base this on the gmpy module > (https://sourceforge.net/projects/gmpy)? That module already provides gmpy wraps GMP, which is covered by LGPL; therefore, gmpy itself is LGPL, and thus, sadly, cannot be included with python (otherwise, speaking as gmpy's author, I'd be glad to fix its design to meet your objections). Alex -- http://mail.python.org/mailman/listinfo/python-list
Re: A rational proposal
[EMAIL PROTECTED] (Alex Martelli) writes: > gmpy wraps GMP, which is covered by LGPL; therefore, gmpy itself is > LGPL, and thus, sadly, cannot be included with python (otherwise, > speaking as gmpy's author, I'd be glad to fix its design to meet your > objections). There's no obstacle to including LGPL'd modules as part of the Python distribution as long as those modules are also offered as source code. The LGPL does place some conditions on how LGPL'd modules can be further redistributed, which users would have to abide by; that might or might not be considered undesirable for Python distro purposes. There's certainly no reason the Python docs can't point to modules like gmpy. They already point to code and documentation that's flat-out proprietary. -- http://mail.python.org/mailman/listinfo/python-list
Re: BASIC vs Python
On Fri, 17 Dec 2004 20:41:11 -0600, Mike Meyer <[EMAIL PROTECTED]> wrote: >Scott Robinson <[EMAIL PROTECTED]> writes: > >> Forth seems better than basic, but is *weird* (I tried it for a >> while). I'm not sure going from Forth to C (or Python) would be much >> easier than Basic to C or Python. The biggest disappointment for >> Forth was that no significant Forth chips were made (and none until it >> was too late). A machine designed to be run on Forth would have been >> unbelievably powerful from the late 70s to the mid 90s (it would be >> more painful now than the x86 legacy, but still). > >I think you overestimate how long the Forth chip would have been a >serious competitor to x`the x86 line. LISP chips - which should have >all the same advantages - didn't last that long. > >http://mail.python.org/mailman/listinfo/python-list
Re: Replace single item in tkinter ListBox
To the best of my knowledge, the only way to do this is as you describe: delete the old item, then insert the new item. The Tk manpage for "listbox" doesn't describe any commands to only update an item in the list. Actually, you may have another choice, if your Tk is new enough---Tk supports (in 8.4, and maybe 8.3) the -listvariable configuration option on listboxes. .>>> t = Tkinter.Tk() .>>> v = Tkinter.Variable(t) .>>> l = Tkinter.Listbox(t, listvariable=v); l.pack() .>>> v.set((1,2,3)) Now, if you assemble a Python sequence 's', you can set the list's contents to that sequence with .>>> v.set(tuple(s)) this still doesn-t allow slice-like updating of listboxes, however. Finally, you could subclass the Tkinter.Listbox, and replace the __setitem__ and __setslice__ methods with methods that manipulate the underlying listbox in the appropriate ways, then create these objects instead of Tkinter.Listbox. I'll leave that as an exercise for the reader. Feel free to contribute the code to the Tkinter wiki (http://tkinter.unpy.net). Jeff pgpWzm7qAW52n.pgp Description: PGP signature -- http://mail.python.org/mailman/listinfo/python-list
Re: Cool object trick
Bengt Richter wrote:
> m=type('',(),{})()
Nick Coghlan wrote:
> Heh.
>
> Look ma, Perlython!
I doubt anyone could perform such a ghastly hack so simply and
straightforwardly in Perl.
--
CARL BANKS
--
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Re: Easy "here documents" ??
Jim Hill wrote:
I've done some Googling around on this and it seems like creating a here
document is a bit tricky with Python. Trivial via triple-quoted strings
if there's no need for variable interpolation but requiring a long, long
formatted arglist via (%s,%s,%s,ad infinitum) if there is. So my
question is:
Is there a way to produce a very long multiline string of output with
variables' values inserted without having to resort to this wacky
"""v = %s"""%(variable)
business?
I have no idea what a "here document" is, but there are several
alternatives to the "wacky" basic substitution with a tuple of
values.
The simplest uses a mapping type:
mydict = {'namedVal': 666}
'''v = %(namedVal)s''' % mydict
Does that let you build whatever a "here document" is?
--
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Re: How do I define the search path for personal library
[EMAIL PROTECTED] wrote: Dear all, i have a simple question. Suppose I have my classes such as myClass1.py myClass2.py etc which I keep in a special folder ~/py_libs Now suppose I have a program that is not in py_libs but I want to do import myClass1 # note: myClass1 is not in the current directory how can I set the search path for python so that it can find myClass1? There are several options, including the PYTHONPATH environment variable, creating a .pth file in site-packages or somewhere (as documented in http://www.python.org/doc/2.4/lib/module-site.html), or even creating your own sitecustomize.py file (also documented in the site.py module docs). What is best depends a bit on your own environment and needs. For example, do you just want this available at the interactive prompt, or to all code you write, or to code that other users on the same system will write? -Peter -- http://mail.python.org/mailman/listinfo/python-list
odbc script
Hello,
I posted a while back about a newbie database question and got a
lot of great help here. My script that I am creating has come a long way
(For me!) and almost does what I need it too. I am basicly using a
dictionary to update a access database using an odbc connector. I am able
to connect and it seems that I am able to loop through the code to update
all the rows I need to. The one weird bug I seem to get is what ever is the
last loop through doesn't seem to update the database?
Here is my code:
**
import dbi
import odbc
invdictionary = {1112:0 ,:0 ,1129:0 ,1139:1 ,1149:1 ,1159:0 ,1169:0
,1179:0 ,1189:1 ,1199:0} # ( key : value )
invd = invdictionary.items() # convert to a list to loop
through
myconn = odbc.odbc('testpy')# connect to database
mycursor = myconn.cursor()
for x in invd:
mycursor.execute('Update Categories Set StockStatus=? Where ProductID=?
;',(x[1], x[0]))# run my sql update
print x[0], x[1] # Just to help me
debug
mycursor.close()
myconn.close()
print invdictionary # Just to help me debug
print invd # Just to help me
debug
Here is the output:
*
1189 1
1159 0
1129 0
1199 0
1169 0
1139 1
0
1112 0
1179 0
1149 1
{1189: 1, 1159: 0, 1129: 0, 1199: 0, 1169: 0, 1139: 1, : 0, 1112: 0,
1179: 0, 1149: 1}
[(1189, 1), (1159, 0), (1129, 0), (1199, 0), (1169, 0), (1139, 1), (,
0), (1112, 0), (1179, 0), (1149, 1)]
After I run this script All the values update correctly except the 1149
value which never changes in the database.
I messed with this for a while and found by adding items to the dictionary
that it never seems to update whatever is the last item to go through the
loop.
I thought I would float it on here and see if this isn't an obvious mistake
that I just can't see. Any help is appreciated.
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Re: Easy "here documents" ??
I was curious so I googled , looks like a unix thing :)
http://www.faqs.org/docs/abs/HTML/here-docs.html
Ok I am with Peter on this , still clueless.
What about string replacement.
py> x = """ Hello me name is ~NAME~. \n I am ~AGE~ years old.\n
...I live in ~CITY~.\n The city of ~CITY~ is nice.\n
...I have live here for ~AGE~ years.\n
... """
py> x = x.replace('~AGE~', '12')
py> x = x.replace('~NAME~', 'Jimmy')
py> x = x.replace('~CITY~', 'Oma')
It makes your template cleaner cause you can use what you want
for the tokens, but takes more lines to do the replacements.
still clueless,
M.E.Farmer
Peter Hansen wrote:
> Jim Hill wrote:
> > I've done some Googling around on this and it seems like creating a
here
> > document is a bit tricky with Python. Trivial via triple-quoted
strings
> > if there's no need for variable interpolation but requiring a long,
long
> > formatted arglist via (%s,%s,%s,ad infinitum) if there is. So my
> > question is:
> >
> > Is there a way to produce a very long multiline string of output
with
> > variables' values inserted without having to resort to this wacky
> >
> > """v = %s"""%(variable)
> >
> > business?
>
> I have no idea what a "here document" is, but there are several
> alternatives to the "wacky" basic substitution with a tuple of
> values.
>
> The simplest uses a mapping type:
>
> mydict = {'namedVal': 666}
> '''v = %(namedVal)s''' % mydict
>
> Does that let you build whatever a "here document" is?
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Re: Easy "here documents" ??
Peter Hansen wrote: Jim Hill wrote: I've done some Googling around on this and it seems like creating a here document is a bit tricky with Python. Trivial via triple-quoted strings if there's no need for variable interpolation but requiring a long, long formatted arglist via (%s,%s,%s,ad infinitum) if there is. So my question is: Is there a way to produce a very long multiline string of output with variables' values inserted without having to resort to this wacky """v = %s"""%(variable) business? I have no idea what a "here document" is, but there are several alternatives to the "wacky" basic substitution with a tuple of values. OP is looking for "heredoc" syntax; in, let's say, PHP this lets you do something like: $foo = new foo(); $name = 'MyName'; echo <bar[1]}. This should print a capital 'A': \x41 EOT; AFAIK, there is no direct Python equivalent for this kind of syntax. Using a mapping like you suggested or the string.Template class in Python 2.4 still maybe improvements over what OP calls that "wacky" business. -- Vincent Wehren The simplest uses a mapping type: mydict = {'namedVal': 666} '''v = %(namedVal)s''' % mydict Does that let you build whatever a "here document" is? -- http://mail.python.org/mailman/listinfo/python-list
Re: Plugin system; imp module head scratch
Dave wrote: Hi, all, I'm trying to implement a simple plugin framework, with some unexpected results. I'm using Python 2.3.4 on Windows 2000. What would be the difference between a "plugin" and a regular Python module? -- ~ Keith Dart <[EMAIL PROTECTED]> public key: ID: F3D288E4 = -- http://mail.python.org/mailman/listinfo/python-list
Re: Plugin system; imp module head scratch
Dave wrote: Hi, all, I'm trying to implement a simple plugin framework, with some unexpected results. I'm using Python 2.3.4 on Windows 2000. My script loader.py loads plugin packages from a directory (in this case its own), and checks a variable defined in the package's __init__.py for information on the plugin. Packages and modules are really rather different beasts. I wouldn't be surprised to find that 'find_module' and 'load_module' behave strangely when used for packages. Is there any reason you can't temporarily alter sys.path and use __import__ normally? The behaviour of that is generally less quirky. Anyway, I believe your specific problem is this line: return imp.load_module(name, None, '', descr) Try replacing the empty string in the third argument with the path returned from the find_module call. (At the moment, it is pulling in the __init__.py from the current directory, and assigning it to the name you requested) Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
Re: Upgrading Python Article
JanC <[EMAIL PROTECTED]> wrote: >Tim Roberts schreef: > >> I don't think that's fair. Visual C++ 7.1 is signficantly better at >> compliance than their past compilers. > >AFAIK that's only for C++, not for C...? Yes. Microsoft has largely chosen to ignore C99. According to the Visual Studio team, there has simply been no demand. -- - Tim Roberts, [EMAIL PROTECTED] Providenza & Boekelheide, Inc. -- http://mail.python.org/mailman/listinfo/python-list
Re: regular expression for javadoc style comment
On Fri, 2004-12-17 at 09:40, Alessandro Crugnola wrote: > Hi all, > i need to use a regular expression to match javadoc style comments in a file, > something like > > /** >* Constructs a new Call instance. >* >* @param object the object the Function shall be executed on >* @param func the Function that shall be executed >* @throws IllegalArgumentException if neigther the object or the > function is not available. >*/ > > i'm finiding many difficulties to write a valid regular expression It would be good if you could post some of the things you've tried, and perhaps a little more detail about what you're trying to match. Are you trying to match the comment as a whole, eg "this is a javadoc comment", or are you trying to extract parts of it? -- Craig Ringer -- http://mail.python.org/mailman/listinfo/python-list
Re: expression form of one-to-many dict?
Steven Bethard <[EMAIL PROTECTED]> wrote:
> map = {}
> for key, value in sequence:
> map.setdefault(key, []).append(value)
I was thinking about exactly that the other day, when converting some
perl to python.
[ digression: In perl, you do
push @{$map->{$key}}, $value
If $map->{$key} doesn't exist is is autovivified into an array (since
its in array context). Now thats exactly the sort of magic that gives
perl a bad name ;-) ]
However, one thing I noticed is that a list is created and destroyed
as the second parameter to setdefault whether or not it is used in
map, which strikes me as a bit wasteful. You obviously can't use the
same list there either. If it was an object with a more expensive
constructor then you'd notice it more.
It would be nice if setdefault didn't evaluate the second argument
unless it needed it. However I guess it would have to be a language
feature to do that.
Here are some timings
$ /usr/lib/python2.3/timeit.py -s 'sequence=zip(range(1000),range(1000))' 'map
= {}
for key, value in sequence:
map.setdefault(key, []).append(value)'
1000 loops, best of 3: 1.42e+03 usec per loop
$ /usr/lib/python2.3/timeit.py -s 'sequence=zip(range(1000),[ i%11 for i in
range(1000)])' 'map = {}
for key, value in sequence:
map.setdefault(key, []).append(value)'
1000 loops, best of 3: 1.57e+03 usec per loop
$ /usr/lib/python2.3/timeit.py -s 'sequence=zip(range(1000),range(1000))' 'map
= {}
for key, value in sequence:
if map.has_key(key):
map[key].append(value)
else:
map[key] = [ value ]'
1000 loops, best of 3: 1.1e+03 usec per loop
$ /usr/lib/python2.3/timeit.py -s 'sequence=zip(range(1000),[ i%11 for i in
range(1000)])' 'map = {}
for key, value in sequence:
if map.has_key(key):
map[key].append(value)
else:
map[key] = [ value ]'
1000 loops, best of 3: 1.11e+03 usec per loop
Not that timing is everything of course ;-)
--
Nick Craig-Wood <[EMAIL PROTECTED]> -- http://www.craig-wood.com/nick
--
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Re: Easy "here documents" ??
Jim Hill wrote: Is there a way to produce a very long multiline string of output with variables' values inserted without having to resort to this wacky """v = %s"""%(variable) business? Try combining Python 2.4's subprocess module with its string Templates. Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://boredomandlaziness.skystorm.net -- http://mail.python.org/mailman/listinfo/python-list
Re: Use macros in Excel via win32com
chris wrote: I'm creating an excel document dynamically from scratch using Python and the win32com module. All is well, but now I need to add a macro to the spreadsheet and run it (to enable some sorting features in the spreadsheet). I think I know how to run a macro once it's installed (using the Run method of the excel application object...I think), but I can't figure out how to "install" the VBA macro code into the spreadsheet to begin with from my Python script. Any tips appreciated. Make a xla in Excel including your VBA macro first and then create your spreadshet from python using that xla as template. -- Greg -- http://mail.python.org/mailman/listinfo/python-list
Re: A completely silly question
On Sat, 2004-12-18 at 00:40, Amir Dekel wrote:
> This must be the silliest question ever:
>
> What about user input in Python? (like stdin)
> Where can I find it? I can't find any references to it in the documentation.
Under UNIX, I generally either use curses, or just put the terminal into
raw mode:
.>>> def sane():
os.system("stty sane")
.>>> def raw():
os.system("stty raw")
.>>> raw()
.>>> x = sys.stdin.read(1)
a
.>>> sane()
.>>> x
'a'
but that's more for the benefit of others here, since you're on Windows.
Needless to say this isn't portable.
It can often be worth also using the 'echo' and 'noecho' arguments to
stty to prevent characters getting echoed in ugly places. If you do much
of this, it's probably worth just using curses, but if you have a fairly
basic app that just needs to read raw characters sometimes this approach
should be fine.
--
Craig Ringer
--
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Re: Use macros in Excel via win32com
Thanks, but the problem is that I need to create the entire Excel document from scratch, dynamically, via the Python script. I want the script to add the macro code. -Chris -- http://mail.python.org/mailman/listinfo/python-list
Re: BASIC vs Python
Dennis Lee Bieber wrote: > Ah, but you said "standard" module for Python... The > graphics/sound extensions on your TI 99/4A were not "standard" BASIC... I assume by "standard" you mean some sort of formal standard, like ANSI Basic or ISO C? If so, well, there's no "standard" Python. What I meant is a widely used implementation. Perhaps "off-the-shelf" would have been an alternative word choice. On thing I should mention is that I'm talking about Extended BASIC, which came on a cartridge and was much more fun than the built-in BASIC. Ahh, and while I gave an example with the PLAY command that was from GW-BASIC on my Heathkit. For the TI you needed to enter the frequencies. I still remember that A is 440 Hz and C is 262. > Go to a different computer, and the commands would likely be much > different -- and if the command was the same, the range of pixels might > vary. Or even the shape of the pixel, as the TRS-80 had distinctly rectangular ones. I don't follow your point though. In the early 1980s there were no microcomputers with standard anything. What programs, other than some trivial BASIC ones, could be ported to other platforms without change? > Hmmm, as I recall, the 99/4A didn't use BASIC as the "native" > level, but actually ran it on top of another specialized interpreter. Don't know. I had migrated to a Heathkit running DOS long before I could understand those details. I've heard that, and looking around now I see you're right. BTW, from http://computermuseum.50megs.com/brands/ti994a.htm here's the specs for that machine 3.3MHz, 26 K ROM, 16.25 K RAM, 32x24 character display @ 16 colors, 40x24 @ 2 colors, 256x192 graphics, 3 channels of sound, US$525 in 1981. Worse than just about any mobile phone these days. And there's even an emulator, for people with the old ROMs hanging around. Wonder if my parents still have my old computers . Andrew [EMAIL PROTECTED] -- http://mail.python.org/mailman/listinfo/python-list
