Burton Samograd wrote:
> Duncan Booth <[EMAIL PROTECTED]> writes:
>
>
>>Burton Samograd wrote:
>>
>>>Is there any way to 'prototype' functions in python, as you would in
>>>C? Would that be what the 'global' keyword is for, or is there a more
>>>elegant or 'pythonic' way of doing forward references?
>>>
>>
>>There isn't really such a thing as a forward reference in Python. Always
>>remember that 'def' and 'class' are executable statements:
>
>
> Ok, we'll here's what I'm trying to do. I have a dictionary that I
> would like to initialize in a module file config.py:
>
> -- config.py -------------------------
> global a_fun, b_fun
> dict = {
dont use 'dict' as an identifier, it shadows the builtin dict type.
> 'a': a_fun,
> 'b': b_fun
> }
> --------------------------------------
>
> where a_fun and b_fun are in fun.py:
>
> -- fun.py ----------------------------
> def a_fun(): pass
> def b_fun(): pass
Until this point, everything is (almost) fine. You'd just need to
rewrite config.py so it imports a_fun and b_fun from fun.py:
#-- config.py -------------------------
import fun
conf = {
'a': fun.a_fun,
'b': fun.b_fun
}
# --------------------------------------
But then, we have this :
> import config
And then we have a circular import...
*But* is it necessary to have the main() in the same file that defines
a_fun and b_fun ? It's quite common (and not only in Python) to use a
distinct file for the main(). So you can easily solve your problem by
splitting fun.py into fun.py and main.py:
#-- main.py -------------------------
import config
def main(*args):
config.dict['a']()
config.dict['b']()
# here we have a python trick:
if __name__ == '__main__':
import sys
sys.exit(main(*sys.argv[1:])
# --------------------------------------
> I like having the module/namespace seperation with the configuration
> variables but I would like to make them easily (re)defined in the
> configuration file by the user.
You may want to look at one of the existing configuration modules.
> Does python have the idea of a 'weak'
> reference
Yes, but that's something totally different.
(snip)
HTH
--
bruno desthuilliers
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p in '[EMAIL PROTECTED]'.split('@')])"
--
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