How to get the seconds since epoch from the time + date output of gmtime()?

Question

How do you do reverse gmtime(), where you put the time + date and get the number of seconds?

I have strings like \'Jul 9, 2009 @ 20:02:58 UTC\'

Answer 1

Note that time.gmtime maps timestamp 0 to 1970-1-1 00:00:00.

In [61]: import time       
In [63]: time.gmtime(0)
Out[63]: time.struct_time(tm_year=1970, tm_mon=1, tm_mday=1, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=3, tm_yday=1, tm_isdst=0)

time.mktime(time.gmtime(0)) gives you a timestamp shifted by an amount that depends on your locale, which in general may not be 0.

In [64]: time.mktime(time.gmtime(0))
Out[64]: 18000.0

The inverse of time.gmtime is calendar.timegm:

In [62]: import calendar    
In [65]: calendar.timegm(time.gmtime(0))
Out[65]: 0