Python optional parameters

Question

Guys, I just started python recently and get confused with the optional parameters, say I have the program like this:

class B:
   pass

class A:
    def __in         


        

Answer 1

Yes; default parameters are evaluated only at the time when the function is defined.

One possible solution would be to have the parameter be a class rather than an instance, a la

def foo(blah, klass = B):
    b = klass()
    # etc