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From: WH on 9 Jun 2010 01:29
Hi,

I want to use one of two functions in a script:

def func_one(): pass
def func_two(): pass

func = getattr(x, 'func_'+number)
func()

'x' in getattr() should be a reference to the "__main__" module, right?
How to get it? The 'if' clause should work here. I am just curious if
we can use the above method.

Thanks,
-WH
From: Steven D'Aprano on 9 Jun 2010 01:41
On Tue, 08 Jun 2010 22:29:04 -0700, WH wrote:

> Hi,
>
> I want to use one of two functions in a script:
>
> def func_one(): pass
> def func_two(): pass
>
> func = getattr(x, 'func_'+number)
> func()
>
> 'x' in getattr() should be a reference to the "__main__" module, right?
> How to get it?


# File test.py
def func_one():
return "one = 1"

def func_two():
return "two = 2"

if __name__ == '__main__':
import __main__
func = getattr(__main__, 'func_' + 'two')
print func()

import test
print getattr(test, 'func_' + 'one')()


which works, but importing yourself can be tricky. Try taking the "if
__name__" test out and running the script and see what happens.


This is probably a better way to solve your problem that doesn't rely on
the module importing itself:


def func_one():
return "one = 1"

def func_two():
return "two = 2"

funcs = {'one': func_one, 'two': func_two}

print funcs['one']



--
Steven
From: Chris Rebert on 9 Jun 2010 01:42
On Tue, Jun 8, 2010 at 10:29 PM, WH <whzhao(a)gmail.com> wrote:
> Hi,
>
> I want to use one of two functions in a script:
>
> def func_one(): pass
> def func_two(): pass
>
> func = getattr(x, 'func_'+number)
> func()
>
> 'x' in getattr() should be a reference to the "__main__" module, right?
>  How to get it?

from sys import modules
__main__ = modules["__main__"] # or call the variable whatever you want
assert __main__.__dict__ is globals() # purely for pedagogy
func = getattr(__main__, 'func_'+number)

Of course, in your particular case, the code can be simplified to
avoid getattr() altogether:

func = globals()['func_'+number]

Cheers,
Chris
--
http://blog.rebertia.com
From: Aahz on 13 Jun 2010 12:40
In article <hun8s4$h4l$1(a)news.albasani.net>, WH <whzhao(a)gmail.com> wrote:
>
>'x' in getattr() should be a reference to the "__main__" module, right?
>How to get it?

Just for the record, the best way to get a reference to __main__ is to
import it:

import __main__
--
Aahz (aahz(a)pythoncraft.com) <*> http://www.pythoncraft.com/

"If you don't know what your program is supposed to do, you'd better not
start writing it." --Dijkstra
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