Python MRO and Passing kwargs through super()

Question

I'm using Python 2.7 on Ubuntu 13.04. I'm building out a series of scheduled tasks to upload some data to a 3rd party API. I'm trying to build the tasks in a generic way so we can easily add more later. In doing so I've used some inheritance techniques that aren't working the way I expect. I think the MRO is pretty straight forward, but I must be doing something wrong because I get global name 'UpdateBase' is not defined when trying to initialize the tasks.

Below is the inheritance structure I'm using.

class UpdateBase(PeriodicTask):
    def __init__(self, table_type=None, update_type=constants.UPDATE_REALTIME,
                 cache_time=constants.CACHE_TIME_UPDATE):
        super(UpdateBase, self).__init__()
        self.table_type = table_type
        self.update_type = update_type
        self.cache_time = cache_time
        self.filename = '{}-{}.{}'.format(
            table_type, datetime.datetime.now(), self.update_type)
        self.old_files = '{}-*'.format(table_type)
        self.file_path = os.path.join(
            constants.UPDATE_FILE_PATH, self.filename)


class UpdateAffiliates(UpdateBase):
    def __init__(self, **kwargs):
        super(UpdateAffiliates, self).__init__(
            table_type=constants.AFFILIATES, **kwargs)


class OverlapAffiliates(UpdateAffiliates):
    def __init__(self, **kwargs):
        super(OverlapAffiliates, self).__init__(
            update_type=constants.UPDATE_OVERLAP,
            cache_time=constants.UPDATE_OVERLAP, **kwargs)

Any suggestions as to why I'm getting this error?

EDIT1:

It seems something else must be causing this NameError. I've built several hierarchies testing this MRO. I've tested every which way I can think of and everything is fine. If anyone can think of anything I can check, change or include to help I would appreciate it.

One example of test code:

#!/usr/bin/env python

CONST1 = 'const_1'
CONST2 = 'const_2'
CONST3 = 'const_3'


class Test1(object):
    internal_val = 'internal 1'

    def __init__(self, val1=None, val2=CONST2, val3=CONST3):
        print 'val1: {}\nval2: {}\nval3: {}\ninternal_val: {}'.format(
            val1, val2, val3, self.internal_val)


class Test2(Test1):
    def __init__(self, **kwargs):
        super(Test2, self).__init__(val1=CONST1, **kwargs)


class Test3(Test2):
    internal_val = 'internal 3'

    def __init__(self, **kwargs):
        super(Test3, self).__init__(
            val2='test3 val2', val3='test3 val3', **kwargs)


def main():
    test1 = Test1()
    test2 = Test2()
    test3 = Test3()

if __name__ == '__main__':
    main()

Answer 1

I was able to solve my problem by moving away from doing my initializations in the __init__() method. Instead I used a base setup_info() method. I raise a NotImplementedError in the base and just write the setup within each child. No big deal, but not as elegant. :)

I'd still like to know what the underlying cause of this problem was. I was inheriting from the celery PeriodicTask. Nothing fancy.