python find end of month

import calendar
from datetime import datetime

year = 2020
month = 1

rng = calendar.monthrange(year, month)  # (2, 31)
last_day = datetime(year, month, rng[1])

# calendar.monthrange returns tuple in the format of
# (<day of week>, <last day>). day of week is 0 indexed
# starting on Monday
#
# 0 = Monday
# 1 = Tuesday
# 2 = Wednesday
# 3 = Thursday
# 4 = Friday
# 5 = Saturday
# 6 = Sunday