ugh, 2.6. `;)`

ok, so let's shorten it slightly -- in particular, i'd like to just copy the existing code from the stdlib (maybe even leaving a note saying "TODO: switch to total_seconds when we drop 2.6 compatibility"):

    return ((time_delta.days * 86400 + time_delta.seconds)*10**6 +
             time_delta.microseconds) / 10**6