Multiple questions concerning Python

[topaz]

1. What, if there is, the equivalent of SendMessage() in Python?
2. How do you make calls to DLLs written in C++ and, if possible, VB6?
3. What library is used for socket work? (hard to phrase... see: mswinsck.dll from VB6)
4. Are optimizations automatically done by the interpreter?

[MyndFyre]

I'm pretty sure I can answer question 2 for you, but don't take it as canon.

C++ DLLs are specialized DLLs -- linkers have to do special work to import them.  This is because, to avoid overlap in function names, they're mangled in a very specific way.  You most likely can't import C++ DLLs unless they expose COM through ATL, which leads me to my response about VB6.  Unless Python provides a way to access COM, you're out of luck with VB6, since VB6 doesn't compile traditional PE DLLs.

[Yegg]

1. What, if there is, the equivalent of SendMessage() in Python?

Well, Python can interface with the Windows API.

2. How do you make calls to DLLs written in C++ and, if possible, VB6?

http://starship.python.net/crew/theller/ctypes/

3. What library is used for socket work? (hard to phrase... see: mswinsck.dll from VB6)

Python has it's own socket library which is very easy to use.

4. Are optimizations automatically done by the interpreter?

I believe so, I'm no Python expert.

[MyndFyre]

http://starship.python.net/crew/theller/ctypes/

He said C++.  Meaning, he wants to use C++ classes.  C DLLs and C++ DLLs are very different.

[Yegg]

http://starship.python.net/crew/theller/ctypes/

He said C++.  Meaning, he wants to use C++ classes.  C DLLs and C++ DLLs are very different.

I havn't used ctypes in quite some time, but does it not support both types of DLLs? Also, what makes the two DLLs different?

[topaz]

1. What, if there is, the equivalent of SendMessage() in Python?

Well, Python can interface with the Windows API.

2. How do you make calls to DLLs written in C++ and, if possible, VB6?

http://starship.python.net/crew/theller/ctypes/

3. What library is used for socket work? (hard to phrase... see: mswinsck.dll from VB6)

Python has it's own socket library which is very easy to use.

4. Are optimizations automatically done by the interpreter?

I believe so, I'm no Python expert.

Would you like to specify, instead of just giving yes or no answers?

[Banana fanna fo fanna]

1. If you've downloaded the win32 extensions for Python (and I'm sure you have, they're usually installed automatically, http://starship.python.net/crew/mhammond/):

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import win32api
win32api.SendMessage(...)
import win32con # for constants


2. You'll probably want to use ActiveX. See http://www.python.org/windows/win32com/QuickStartClientCom.html . You also might want to wrap a C library around it and use ctypes, which is included in Python 2.5, and available at the link above.

3. Most people just use the built-in socket library ("import socket") and maybe non-blocking I/O ("import select"). If you want to access HTTP URLs, "import urllib2", or if you want to serve up web pages, "import SimpleHTTPServer". If you're looking for a hardcore (and I mean hardcore) networking framework built on Python, see www.twistedmatrix.com.

4. Yeah. If you need any more, Psyco is your man (http://psyco.sourceforge.net/). All you have to do is:

Code Select Expand


import psyco
psyco.full()


[topaz]

Thanks!

[topaz]

I'll continue to add questions as I run into problems:


5. What is / how would I use arg? I've seen it around, but I can't find any documentation on it (checked MSDN, Google - just code involving it, no explanations).

[FrOzeN]

5. What is / how would I use arg? I've seen it around, but I can't find any documentation on it (checked MSDN, Google - just code involving it, no explanations).

Not sure if this is what you ment, but I'll take a stab.

If you mean 'arg' as-in 'argc/argv', eg:

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int main(int argc, char *argv[]);
Then argc is an integer containing the amount of arguements (determined by spaces) that are in the command line, and argv[] would be a character array with each part.

Eg, If you did ran the program like "yourprogram.exe Hello Something -c -bla"
argc would be 4, argv[0] would be "Hello", argv[1] = "Something", argv[2] = "-c" and argv[4] = "-bla".

[EDIT] Eh, that was C++. Anyway 'arg' essentially stands for "Command Line Arguments". This will explain it better for Python.

[Banana fanna fo fanna]

Code Select Expand


import sys
print sys.argv


[rabbit]

5. What is / how would I use arg? I've seen it around, but I can't find any documentation on it (checked MSDN, Google - just code involving it, no explanations).

Not sure if this is what you ment, but I'll take a stab.

If you mean 'arg' as-in 'argc/argv', eg:

Code Select Expand

int main(int argc, char *argv[]);
Then argc is an integer containing the amount of arguements (determined by spaces) that are in the command line, and argv[] would be a character array with each part.

Eg, If you did ran the program like "yourprogram.exe Hello Something -c -bla"
argc would be 4, argv[0] would be "Hello", argv[1] = "Something", argv[2] = "-c" and argv[4] = "-bla".

[EDIT] Eh, that was C++. Anyway 'arg' essentially stands for "Command Line Arguments". This will explain it better for Python.

You're almost correct.  In C/++, argv[0] is always how the program name.  IE: if you did 'yourprogram.exe Hello Stuff', argv[0] would be "yourprogram.exe", but if you did 'yourprogram Goodbye Moo', argv[0] would be "yourprogram".

[topaz]

Thanks, everyone.

[Kp]

You're almost correct.  In C/++, argv[0] is always how the program name.  IE: if you did 'yourprogram.exe Hello Stuff', argv[0] would be "yourprogram.exe", but if you did 'yourprogram Goodbye Moo', argv[0] would be "yourprogram".

You too, are almost correct.   argv[0] is chosen by the calling application, just as all other argv[] values are.  It's traditional for shells to place the program's name in argv[0], but they're not required to do so.

[rabbit]

Windows does it, and based on what's been said, that's the primary platform, so that's what I went with.