super function doesn't work inside a maya python module

Somehow, this works fine in the Maya/Python script editor开发者_如何学Go, but fails when it's inside of my module code. Anyone have any ideas?

class ControlShape(object):
    def __init__(self, *args, **kwargs):
        print 'Inside ControlShape...'

class Cross(ControlShape):
    def __init__(self, *args, **kwargs):
        print 'Entering Cross...'
        super(Cross, self).__init__(*args, **kwargs)
        print 'Leaving Cross...'

x = Cross()

This gives me a TypeError: super(type, obj): obj must be an instance or subtype of type.

It has to do with reloading modules. Reloading a module often changes the internal object in memory which makes the isinstance test of super return False.

http://thingspython.wordpress.com/2010/09/27/another-super-wrinkle-raising-typeerror/

I had this exact same problem. It's definitely not practical to restart maya each time you make a change. I found an answer here that solved this problem for me.

You should read the linked answer to understand why its only suitable for debugging. But briefly, put this code in userSetup.py, then each time you edit your code run reload_package(my_package)

import sys, types
def reload_package(root_module):
    package_name = root_module.__name__

    # get a reference to each loaded module
    loaded_package_modules = dict([
        (key, value) for key, value in sys.modules.items() 
        if key.startswith(package_name) and isinstance(value, types.ModuleType)])

    # delete references to these loaded modules from sys.modules
    for key in loaded_package_modules:
        del sys.modules[key]

    # load each of the modules again; 
    # make old modules share state with new modules
    for key in loaded_package_modules:
        print 'loading %s' % key
        newmodule = __import__(key)
        oldmodule = loaded_package_modules[key]
        oldmodule.__dict__.clear()
        oldmodule.__dict__.update(newmodule.__dict__)

It is good rule of thumb if you're using the super(Class, self).__init__ that you ALWAYS call it this way. This applies to your classes that inherit from object.

class ControlShape(object):
   def __init__(self, *args, **kwargs):
      super(ControlShape, self).__init__()
      print 'Inside ControlShape...'

See if that fixes your error. Just a guess as I don't use maya, but worth a shot.

Turns out it had something to do with my imports at the top of the module. I forget which one it was, though. I should have posted this the moment I discovered what it was.