将日期字符串转换为日期格式，然后做减法

Question

I am given two dates as string below, and I want to subtract to get a number 16 as my output. i tried convert them to date format first and do the math but it didn't work. Thanks in advance

from datetime import datetime

date_string = '2021-05-27'

prev_date_string = '2021-05-11'

a= datetime.strptime(date_string '%y/%m/%d')

b =datetime.strptime(prev_date_string '%y/%m/%d')

c= ab

print (c)

Answer 1

There are two problems with the strptime calls. First, they are missing commas ( , ) between the two arguments. Second, the format string you use must match the format of the dates you have.

Also, note the result of subtracting two datetime objects is a timedelta object . If you just want to print out the number 16, you'll need to extract the days property of the result:

a = datetime.strptime(date_string, '%Y-%m-%d')
b = datetime.strptime(prev_date_string, '%Y-%m-%d')

c = a-b

print (c.days)

Answer 2

The simple answer for this problem.

from datetime import date

a = date(2021, 5, 11)
b = date(2021, 5, 27)
c = b - a
print(c.days)