Calling a function from string inside the same module in Python?

Question

Lets say I have a function bar inside a module called foo.py . Somewhere inside foo.py, I want to be able to call bar() from the string "bar". How do I do that?

# filename: foo.py
import sys
def bar():
 print 'Hello, called bar()!'
if __name__ == '__main__':
 funcname = 'bar'
 # Here I should be able to call bar() from funcname

I know that there exists some built-in function in python called 'getattr'. However, it requires 'module object' to be the first parameter. How to obtain the 'module object' of the current module?

Answer 1

globals is probably easier to understand. It returns the current module's __dict__, so you could do:

func_I_want = globals()['bar'] #Get the function
func_I_want() #call it

If you really want the module object, you can get it from sys.modules (but you usually don't need it):

import sys.modules
this_mod = sys.modules[__name__]
func = getattr(this_mod,'bar')
func()

Note that in general, you should ask yourself why you want to do this. This will allow any function to be called via a string -- which is probably user input... This can have potentially bad side effects if you accidentally give users access to the wrong functions.

Answer 2

Use a dictionary that keeps the mapping of functions you want to call:

if __name__ == '__main__':
 funcnames = {'bar': bar}
 funcnames['bar']()

• gboffi: I always appreciate an answer that solves the OP's problem rather than her/his question. +1