Chris> I keep needing to know the number of seconds that a timedelta
Chris> represents.

I propose an alternative approach that I believe will neatly solve 
fractional vs. whole seconds and multitude of conceivable toxxx methods:

Let's extend timedelta's div and floordiv methods to allow 

>>> (t - epoch) // timedelta(seconds=1)
--> whole seconds

and  

>>> (t - epoch) / timedelta(seconds=1)
--> fractional seconds