Concrete Factory Pattern syntax?

[Austin Schutz]

I have a fairly simple bit of code, something like:

# This should be importing the subclasses somehow, so that the factory
# can make them.
# import Parser.One
# import Parser.Two
# or.. from Parser import *?
class Parser():
def parse:
'Implemented only in subclass'

def make_parser(which_parser):
if(which_parser = 'one'):
return One()
else:
return Two()

# import Parser?
class One(Parser):
def parse:
'one implementation'

class Two(Parser):
def parse:
'another implementation'

The problem I have is that I don't understand how to put this into
actual files in actual directories and have the interpreter do
something actually useful . What I would like to do is something
like:

lib/
Parser.py
Parser/
__init__.py (maybe?)
One.py
Two.py

But I'm not clear on how to structure the import statements. I'm a bit
of a newb wrt python, and I get any number of different errors depending
on how I arrange the import statements, everything from

AttributeError: 'module' object has no attribute 'make_parser'
to
ImportError: cannot import name
to
TypeError: Error when calling the metaclass bases

depending on how I use import. Nothing seems to be the correct
combination. Any help would be much appreciated!

Austin