personal-data/personal_data/parse_util.py

import datetime

DATETIME_UNITS = {
        'second': datetime.timedelta(seconds = 1),
        'seconds': datetime.timedelta(seconds = 1),
        'minute': datetime.timedelta(minutes = 1),
        'minutes': datetime.timedelta(minutes = 1),
        'hour': datetime.timedelta(hours = 1),
        'hours': datetime.timedelta(hours = 1),
        'day': datetime.timedelta(days = 1),
        'days': datetime.timedelta(days = 1),
        'week': datetime.timedelta(days = 7),
        'weeks': datetime.timedelta(days = 7),
        'month': datetime.timedelta(days = 30),
        'months': datetime.timedelta(days = 30),
        'year': datetime.timedelta(days = 365),
        'years': datetime.timedelta(days = 365),
}

FORMAT_DATE_HEADER = '%a, %d %b %Y %H:%M:%S GMT'

def parse_duration(text: str) -> datetime.timedelta:
    (num, unit) = text.split(' ')
    num = int(num)
    unit = DATETIME_UNITS[unit]
    return unit * num

def response_datetime(response) -> datetime.datetime:
    return datetime.datetime.strptime(response.headers['Date'], FORMAT_DATE_HEADER)