Finding a function's parameters in Python

Question

I want to be able to ask a class\'s __init__ method what it\'s parameters are. The straightforward approach is the following:

cls.__init__.__fu         


        

Answer 1

Consider this decorator:

def rickroll(old_function):
    return lambda junk, junk1, junk2: "Never Going To Give You Up"

class Foo(object):
    @rickroll
    def bar(self, p1, p2):
        return p1 * p2

print Foo().bar(1, 2)

In it, the rickroll decorator takes the bar method, discards it, replaces it with a new function that ignores its differently-named (and possibly numbered!) parameters and instead returns a line from a classic song.

There are no further references to the original function, and the garbage collector can come and remove it any time it likes.

In such a case, I cannot see how you could find the parameter names p1 and p2. In my understanding, even the Python interpreter itself has no idea what they used to be called.