32 lines
945 B
Python
32 lines
945 B
Python
from datetime import datetime, timedelta
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if __name__ == '__main__':
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weekdays = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
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def get_previous_by_day(day_name, start_date=None):
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if start_date is None:
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start_date = datetime.today()
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day_num = start_date.weekday()
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day_num_target = weekdays.index(day_name)
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days_ago = (7 + day_num - day_num_target) % 7
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if days_ago == 0:
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days_ago = 7
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target_date = start_date - timedelta(days=days_ago)
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return target_date
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get_previous_by_day("Friday")
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# 但是如果要经常这么干，请使用dateutil包
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d = datetime.now()
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from dateutil.relativedelta import relativedelta
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from dateutil.rrule import *
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# 找最近的周五，FR是rrule里的函数
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print(d + relativedelta(weekday=FR))
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# 找上一个周五
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print(d + relativedelta(weekday=FR(-1)))
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