According to the different needs, there are two schemes for the calculation of general length of service, one is directly expressed in days, and the other is expressed in the format of mm / DD / yyyy. The calculation methods of the two cases are different, so make a record.

1. In days

Idea: directly subtract two dates to get the number of days

 1 from datetime import datetime
 2 
 3 
 4 def cal_working_age():
 5     current_date = datetime.now().date()
 6     begin_date = datetime.strptime("2010-01-01", "%Y-%m-%d").date()
 7 
 8     return (current_date - begin_date).days
 9 
10 if __name__ == "__main__":
11     print(cal_working_age())

2. In the form of MM DD YY

Idea: reduce year by year, month by month, and day by day. If not, borrow from others. If the month is not enough, then borrow 12 months from the year, so the year should be reduced one more time, and so on.

 1 from datetime import datetime
 2 
 3 
 4 def cal_working_age_format(begin_date_str):
 5     current_date = datetime.now().date()
 6     begin_date = datetime.strptime(begin_date_str, "%Y-%m-%d").date()
 7     begin_year = int(begin_date.year)
 8     begin_month = int(begin_date.month)
 9     begin_day = int(begin_date.day)
10 
11     delta_year = current_date.year - begin_year
12     
13     delta_month = current_date.month - begin_month
14     if delta_month < 0:
15         delta_year -= 1
16         delta_month = 12 + delta_month
17         
18     delta_day = current_date.day - begin_day
19     if delta_day >= 0:
20         pass
21     else:
22         delta_month-=1
23         last_month_days = (datetime.datetime(year=current_date.year, month=current_date.month+1, day=1)-datetime.timedelta(days=1)).day
24         delta_day = last_month_days + delta_day
25 
26     work_age = "{}year{}month{}day".format(delta_year, delta_month, delta_day)
27 
28     return work_age
29 
30 if __name__ == "__main__":
31     begin_date = "2010-01-01"
32     print(cal_working_age_format(begin_date))

TODO: in the future, when encountering other methods of seniority calculation, update them.