calendar如何筛选出python3时间中重复事件?

import calendar

import pprint

pprint.pprint(calendar.monthcalendar(2017, 7))

# 输出

# [[0, 0, 0, 0, 0, 1, 2],

#  [3, 4, 5, 6, 7, 8, 9],

#  [10, 11, 12, 13, 14, 15, 16],

#  [17, 18, 19, 20, 21, 22, 23],

#  [24, 25, 26, 27, 28, 29, 30],

#  [31, 0, 0, 0, 0, 0, 0]]

import calendar

import sys

year = int(sys.argv[1])

# Show every month

for month in range(1, 13):

    # Compute the dates for each week that overlaps the month

    c = calendar.monthcalendar(year, month)

    first_week = c[0]

    second_week = c[1]

    third_week = c[2]

    # If there is a Thursday in the first week,

    # the second Thursday is # in the second week.

    # Otherwise, the second Thursday must be in

    # the third week.

    if first_week[calendar.THURSDAY]:

        meeting_date = second_week[calendar.THURSDAY]

    else:

        meeting_date = third_week[calendar.THURSDAY]

    print('{:>3}: {:>2}'.format(calendar.month_abbr[month], meeting_date))

# 输出   

# Jan: 12

# Feb:  9

# Mar:  9

# Apr: 13

# May: 11

# Jun:  8

# Jul: 13

# Aug: 10

# Sep: 14

# Oct: 12

# Nov:  9

# Dec: 14