Python functions modify whatever arguments you pass in.

Python functions modify whatever arguments you pass in,
and the changes are seen outside the function.

Example code:


dct = dict(a='a', b='b')

def modify_dct(thedct):
    thedct['a'] = 1
    thedct['b'] = 2

if __name__ == '__main__':
    print dct
    modify_dct(dct)
    print dct
    print "OK"

Output:


[Dbg]>>> 
{'a': 'a', 'b': 'b'}
{'a': 1, 'b': 2}
OK



What just happened?
Unlike C, which has pass by value, whatever you pass to a function other than primitives (int, e.g. 1, 110,)
is actually a reference to that object itself, and not a copy.

So, modifying it inside the function will see it changed outside the function, after the func has run (processed it) on it.