Python - Time difference formatting

gistfile1.py

from dateutil.relativedelta import relativedelta

# Calculate the relative timedelta
relative_delta = relativedelta(now_gmt, posted_time_gmt)

relative_time_format = {
    'future' : 'in %s',
    'past' : '%s ago',
    's' : 'a few seconds',
    'm' : 'a minute',
    'mm' : '%d minutes',
    'h' : 'an hour',
    'hh' : '%d hours',
    'd' : 'a day',
    'dd' : '%d days',
    'M' : 'a month',
    'MM' : '%d months',
    'y' : 'a year',
    'yy' : '%d years'
}

# Get the relative time a string format
if relative_delta.years > 0:
    if relative_delta.years > 1:
        relative_delta_string = relative_time_format['yy'] % relative_delta.years
    else:
        relative_delta_string = relative_time_format['y'] % relative_delta.years

elif relative_delta.months > 0:
    if relative_delta.months > 1:
        relative_delta_string = relative_time_format['MM'] % relative_delta.months
    else:
        relative_delta_string = relative_time_format['M'] % relative_delta.months

elif relative_delta.days > 0:
    if relative_delta.days > 1:
        relative_delta_string = relative_time_format['dd'] % relative_delta.days
    else:
        relative_delta_string = relative_time_format['d'] % relative_delta.days

elif relative_delta.hours > 0:
    if relative_delta.hours > 1:
        relative_delta_string = relative_time_format['hh'] % relative_delta.hours
    else:
        relative_delta_string = relative_time_format['h'] % relative_delta.hours

elif relative_delta.minutes > 0:
    if relative_delta.minutes > 1:
        relative_delta_string = relative_time_format['mm'] % relative_delta.minutes
    else:
        relative_delta_string = relative_time_format['m']

else:
    relative_delta_string = relative_time_format['s']

# We only support past for now
delta_string = relative_time_format['past'] % relative_delta_string

return delta_string

####################
# The ago library  #
####################

from ago import human

human(now - posted, precision=2)

# Precision is for how many levels to drill down
# Eg. Precision 1: 2 days ago
# Eg. Precision 2: 2 days ago, 20 hours