Comparing dateutil.relativedelta

dateutil.relativedelta doesn't implement __cmp__ sensibly, so instances can't be compared. There's an open bug on the issue; the argument that it doesn't make sense to say whether 29 days or 1 month is greater, and that therefore the whole thing falls back on python's default comparisons seems a bit flimsy to me, but that's just an opinion.

Depending on what you're actually doing, using datetime.timedelta may be a better solution.