从工作日、月份和日期计算年份

Question

我有一堆没有年份的日期，格式如下：

Thu Apr 10
Mon Mar 28

python中是否有一种简单的方法来识别这些日期来自的年份？

Answer 1

当然会有超过一年有效的情况，但假设你想拿后一年，如果有这种情况，那么这个算法应该可以正常工作。

For each string
    Take the Month(Apr) and the Date(10) 
    For each year from this year down to whenever you'd like to stop
        Make a datetime object with the Month, Date, and Year
        If the datetime object's .weekday is the same as the Day you have (Thu)
            You've found the right year

或者在 python 中，它可能看起来像这样：

import datetime

with open("yourFile") as f:
for line in f:  

    day = #get the day from the line  (0-30)
    month = #get the number representing the month from the line (0-11)

    year = 2016
    while True:
        testDate = datetime.date(year, month, day)
        weekday = #turn the string "Thu" or "Mon" into the number value 
                  #it represents (0-6)
        if testDate.weekday == weekday:
            #You have found a matching year!!!
        else:
            year = year + 1

Answer 2

下面的代码应该可以工作，你必须选择一年开始和一个方向作为step （ -1代表时间倒退， 1代表时间前进），它会给你它遇到的第一年条件为真：

import datetime
weekdays = {'Mon': 0, 'Tue': 1, 'Wed': 2, 'Thu': 3, 'Fri': 4, 'Sat': 5, 'Sun': 6}
months = {'Jan': 1, 'Feb': 2, 'Mar': 3, 'Apr': 4, 'May': 5, 'Jun': 6,
          'Jul': 7, 'Aug': 8, 'Sep': 9, 'Oct': 10, 'Nov': 11, 'Dec': 12}
dates = ['Thu Apr 10', 'Mon Mar 28']
startYear = 2016
step = -1
years = []

for date in dates:
  [weekDay, month, day] = date.split(' ')
  day = int(day)
  year = startYear
  while True:
    if datetime.date(year, months[month], day).weekday() == weekdays[weekDay]:
      years.append(year)
      break;
    else:
      year = year + step