First, thanks for all the thoughtful replies. I am grateful. Second, I figured I'd get a lot of judgement about how I really shouldn't be doing this. Should have pre-empted it :-) oh well. There is a place IMHO for filename as another structuring element to help humans in search. Also it can be convenient to have two people who are working on methods for one class that have different directions to have different files (even if modern tools can handle distinct edits on the same file by multiple folks). Third, length. Well 5000 lines eh... I'm nowhere near that guess I can stick with one file. Steven thanks especially for your thorough reply about alternatives. Again I really appreciate the quality replies made here. very impressed. I had not thought of the mixin approach in particular. I was just hoping there was something like "extend class Foo" I could put at the top of the file and then keep writing methods indented below it. But I will think about some of these alternatives...
Humbly, Luke -- http://mail.python.org/mailman/listinfo/python-list