t.py

class Foo:
        def __init__(self,p):
                print "__init2__"

        def __init__(self): # tem prioridade 
                print "__init__"

        def function(self, param):
                print "function with 1 parameter"

        def function(self, param1, param2):
                print "function with 2 parameters"

        def function(self): # a mesma coisa
                print "function without parameters"

x = Foo()
x.function()