Time ago/Convert time

convert_time_ago.py

import time

def convert_time(conv_time, ago=False):
    """Returns time ago/stuff lol"""
    periods = ["second", "minute", "hour", "day", "week", "month", "year", "decade", "century", "millennium"]
    lengths = [60, 60, 24, 7, 4.35, 12, 10, 10, 10]
    if ago:
        now = time.time()
        difference = now - conv_time
    else:
        difference = conv_time
    j = 0
    while difference >= lengths[j] and j < len(lengths) - 1:
        difference /= lengths[j]
        j += 1
    difference = round(difference)
    if difference != 1:
        periods[j] += "s"
    output = f"{difference} {periods[j]}"
    if ago:
        output = "now" if (difference == 0) else f"{difference} {periods[j]} ago"
    return output