Age Regex

import re

datetime_re = re.compile("(?P<time>(?P<length>\d+)\s*(?P<unit>\w)\s*)")

ages = ['6W', '4M3W', '6Y', '1Y 3M', '16 Y 5M 2 W']

TIME_PER_YEAR = {
    'Y': 1.0,
    'W': 52.0,
    'M': 12.0
}


def age_to_years(length, unit_time):
    try:
        length = int(length)
    except ValueError:
        pass
    return length / TIME_PER_YEAR[unit_time.upper()]


if __name__ == '__main__':
    for time_input in ages:
        print(time_input)
        for datetime_out in datetime_re.finditer(time_input):
            print(datetime_out.groups())
        print(sum(age_to_years(*datetime_out.groups()[1:]) for datetime_out in datetime_re.finditer(time_input)))