Thanks for the patch!  Comments, in increasing order of fussiness:

(1) there should be a Py_DECREF(total_microseconds) in the case that the "PyLong_FromLong(1000000L)" call fails

(2) in the docstring, replace 'loose' by 'lose'

(3) also in the docstring, I suggest replacing "280 years" by "270 years":   "td == timedelta(seconds = td.total_seconds())" starts failing at 2**33 seconds (around 272.2 Julian years) rather than 2**53 microseconds.