Python: functions has to be define first in the code to work?

[tjansson]

I probably misunderstood something but as I see it now I need to define a function before a call in Python. This makes sense when thinking of Python as a scripting language - but I am using it as programming language and this problem really makes my code look ugly and confusing.

Did I misunderstand something or is there really no way around this?

[LaRoza]

That happens in many languages.

To make the code clean, put the function in a different file, then import them.

This also makes them reusable.

[EndPerform]

I think it's a matter of taste, personally. I like having my functions and classes up top. To eliminate confusion, just comment your code:

import os

# ---- Start Functions ----#

# some_func - A cool function
def some_func():
   print "hi"

# ---- End Functions ---- #

some_func()

I do agree, though, if you have code you're going to reuse in other apps, go ahead and move that out to a separate file.

[pmasiar]

as I see it now I need to define a function before a call in Python. This makes sense when thinking of Python as a scripting language - but I am using it as programming language and this problem really makes my code look ugly and confusing.

Not sure how you differentiate between "scripting" and "programming" , and how writing readable code makes your code ugly.

But order you mentioned is necessary - you wished for fast single-pass source code parser, didn't you? So you got your wish. Be more careful next time.

I hazard to guess you have huge main program with some functions at the end. You can easily convert it to this format:

def main():
    sub1()
    sub2()

def sub1():
    # code
def sub2():
    # code

if __name__ == "__main__":
    main()

See also Guido's blog post about writing main() the right way. And trust me, Guido knows what he is talking about

This way, your module will run main() if called as main program, and not run it if imported. You can have your cake and eat it too.

[SomethingUniqueHere]

Functions gotta go first, any procedural code goes at the bottom. Importing of functions is nice to do but not always practical depending on what they do. Also, i found this really confusing when i just got into python -

if __name__ == "__main__":
    main()

That's something you only need if you ever plan on importing this file as a module in another. It essentially says "if you're running this as a script then execute main" but if you're importing it to another program nothing is going to execute unless explicitly called.

Hope that clears stuff up

[pmasiar]

if doing it flexible and right is confusing, instead of

if __name__ == "__main__":
    main()

do just at the last line

main()

and make sure you do not import that module (because main() would be executed).

[tjansson]

Thanks for the advice guys. My problems is that I have a class for some buttons. The buttons have a disable method but I can't disable a given button before I have initiated it - this makes sense off course but It makes the code look bad since I have initiate all the button in top and draw later on.

[pmasiar]

wrong. just put all code you have in top (module) level into a main() function, and call this function at last line.

names have to be known only at at execution time - can you post your (simplified) code sample?