Python Introspection: How to get varnames of class methods?

Question

I want to get the names of the keyword arguments of the methods of a class. I think I understood how to get the names of the methods and how to get the variable names of a specific method, but I don't get how to combine these:

class A(object):
    def A1(self, test1=None):
        self.test1 = test1
    def A2(self, test2=None):
        self.test2 = test2
    def A3(self):
        pass
    def A4(self, test4=None, test5=None):
        self.test4 = test4
        self.test5 = test5

a = A()

# to get the names of the methods:

for methodname in a.__class__.__dict__.keys():
    print methodname

# to get the variable names of a specific method:

for varname in a.A1.__func__.__code__.co_varnames:
    print varname

# I want to have something like this:
for function in class:
    print function.name
    for varname in function:
        print varname

# desired output:
A1
self
test1
A2
self
test2
A3
self
A4
self
test4
test5

I will have to expose the names of the methods and their arguments to an external API. I have written a twisted app to link to the mentioned api and this twisted app will have to publish this data via the api.

So, I think I will use something like:

for methodname in A.__dict__.keys():
if not methodname.startswith('__'):
    print methodname
    for varname in A.__dict__[methodname].__code__.co_varnames:
        print varname

Once, the surroundings get more stable I will think about a better solution.

Answer 1

Well, as a direct extension of what you did:

for varname in a.__class__.__dict__['A1'].__code__.co_varnames:
    print varname

prints:

self
test1

P.S.: to be honest, I have a feeling this can be done more elegantly...

For example, you can replace a.__class__ with A, but you knew that ;-)

Answer 2

import inspect

for name, method in inspect.getmembers(a, inspect.ismethod):
    print name
    (args, varargs, varkw, defaults) = inspect.getargspec(method)
    for arg in args:
        print arg