Calling an arbitrary function with the right arguments

[John O'Hagan]

How to call a function with the right arguments without knowing in advance 
which function? For example:

import random

def f1():
    pass

def f2(foo):
    pass

def f3(foo, bar):
    pass

foo=random.choice((1,2,3))
bar=random.choice((1,2,3))

myfunc=random.choice((f1, f2, f3))

How to call myfunc with the right arguments?
I've been doing it this way:

f1.args=()
f2.args=('foo',)
f3.args=('foo', 'bar')

args=[vars()[i] for i in myfunc.args]

myfunc(*args)

But it seems redundant to manually tag the functions with their own arguments' 
names, and I don't like using vars(). Is there a nicer pattern? 

Regards,

John