On Sun, Aug 11, 2013 at 4:41 AM, Jason Friedman <jsf80...@gmail.com> wrote: > class my_class: > def __init__(self, attr1, attr2): > self.attr1 = attr1 #string > self.attr2 = attr2 #string > def __lt__(self, other): > if self.attr1 < other.attr1: > return True > else: > return self.attr2 < other.attr2 > > I will run into problems if attr1 or attr2 is None, and they > legitimately can be. > > I know I can check for attr1 or attr2 or both being None and react > accordingly, but my real class has ten attributes and that approach > will be long. What are my alternatives?
The first question is: What should the comparison do with a None value? Should it be considered less than every string? If so, you could simply use: if (self.attr1 or "") < (other.attr1 or ""): which will treat any falsy value as blank. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
