readable_time_elapsed.py

from datetime import datetime


def readable_time_elapsed(since):
    """
    Generates a string with an informal English text representation of the
    time that has elapsed between now and a given time.

    Modified from some StackOverflow answer that I have lost.

    :param since:
    :return:
    """
    delta = datetime.now() - since
    seconds_delta = delta.seconds
    days_delta = delta.days

    if days_delta < 0:
        return ''

    if days_delta == 0:
        if seconds_delta < 10:
            return "Just now"
        if seconds_delta < 60:
            return "{0} seconds ago".format(seconds_delta)
        if seconds_delta < 120:
            return "A minute ago"
        if seconds_delta < 3600:
            return "{0} minutes ago".format(seconds_delta // 60)
        if seconds_delta < 7200:
            return "An hour ago"
        if seconds_delta < 86400:
            return "{0} hours ago".format(seconds_delta // 3600)

    if days_delta == 1:
        return "Yesterday"
    if days_delta < 7:
        return "{0} days ago".format(days_delta)
    if days_delta < 31:
        num_weeks = days_delta // 7
        if num_weeks == 1:
            return "A week ago"
        return "{0} weeks ago".format(num_weeks)
    if days_delta < 365:
        num_months = days_delta // 30
        if num_months == 1:
            return "A month ago"
        return "{0} months ago".format(num_months)

    return "{0} years ago".format(days_delta // 365)