如何从星期几获取月几号？

Question

I'm trying to get python to return the date of the month when a day of the week is inputed eg: 1st Sunday of April 2018 returns 1 or 3rd Thursday of April 2018 returns 19

Are there python libraries or mathematical algorithms that do this? I've looked at Zeller's congruence but it seems like it does the opposite.

Answer 1

From your Input string separating all the values and then takes all the dates of that day from that month in that year.

Here a big try :

import calendar
import re

c = calendar.Calendar(firstweekday=calendar.SUNDAY)

string = "1st Sunday of April 2018"
string.split().pop(2)
string_list = string.split()
year = int(string_list[4])
month = list(calendar.month_name).index(string_list[3])
day_num = list(calendar.day_name).index(string_list[1])
which = int(re.search(r'\d+', string_list[0]).group())

monthcal = c.monthdatescalendar(year,month)
date = [day for week in monthcal for day in week if \
            day.weekday() == day_num and \
            day.month == month][which-1]

print(date.day)