How can I produce a human readable difference when subtracting two UNIX timestamps using Python?

Question

This question is similar to this question about subtracting dates with Python, but not identical. I\'m not dealing with strings, I have to figure out the difference between

Answer 1

I had that exact same problem earlier today and I couldn't find anything in the standard libraries that I could use, so this is what I wrote:

humanize_time.py

    #!/usr/bin/env python

    INTERVALS = [1, 60, 3600, 86400, 604800, 2419200, 29030400]
    NAMES = [('second', 'seconds'),
             ('minute', 'minutes'),
             ('hour', 'hours'),
             ('day', 'days'),
             ('week', 'weeks'),
             ('month', 'months'),
             ('year', 'years')]

    def humanize_time(amount, units):
    """
    Divide `amount` in time periods.
    Useful for making time intervals more human readable.

    >>> humanize_time(173, 'hours')
    [(1, 'week'), (5, 'hours')]
    >>> humanize_time(17313, 'seconds')
    [(4, 'hours'), (48, 'minutes'), (33, 'seconds')]
    >>> humanize_time(90, 'weeks')
    [(1, 'year'), (10, 'months'), (2, 'weeks')]
    >>> humanize_time(42, 'months')
    [(3, 'years'), (6, 'months')]
    >>> humanize_time(500, 'days')
    [(1, 'year'), (5, 'months'), (3, 'weeks'), (3, 'days')]
    """
       result = []

       unit = map(lambda a: a[1], NAMES).index(units)
       # Convert to seconds
       amount = amount * INTERVALS[unit]

       for i in range(len(NAMES)-1, -1, -1):
          a = amount / INTERVALS[i]
          if a > 0:
             result.append( (a, NAMES[i][1 % a]) )
             amount -= a * INTERVALS[i]

       return result

    if __name__ == "__main__":
        import doctest
        doctest.testmod()

You can use dateutil.relativedelta() to calculate the accurate time delta and humanize it with this script.