What is a proper way of doing a substraction with datetime

Question

I have a datetime variable and I want to substract just 1 hour from it. I tried to do it with below code but I received the following error: TypeError: unsupported operand type(s) for -: 'str' and 'datetime.timedelta'

from datetime import datetime, timedelta

cur_time = datetime.now()
cur_time_f = cur_time.strftime("%Y-%m-%dT%H:%M:%SZ")  
print(cur_time_f)

>> 2020-09-15T09:07:44Z

nueve = cur_time_f - timedelta(hours=1)

print(nueve)

My expected output:

>> 2020-09-15T08:07:44Z

@mkrieger1 Yes that one is working. But I need the format im using in `cur_time_f` — NorthAfrican, Sep 15 '20 at 07:14
A string is a string, you can't do time calculations with it. A `datetime` object is something you can do time calculations with. You can format a `datetime` object to a string using `strftime`. Do your calculations on `datetime` objects and format them using `strftime` when and only when you want to output it. — deceze, Sep 15 '20 at 07:21

score 1 · Accepted Answer · answered Sep 15 '20 at 07:32

Do the calculation BEFORE turning it into a string

from datetime import datetime, timedelta

cur_time = datetime.now()
print(cur_time)

>>2020-09-15 11:29:51.756391

cur_time = cur_time - timedelta(hours=1)
cur_time_f = cur_time.strftime("%Y-%m-%dT%H:%M:%SZ")  
print(cur_time_f)

>>2020-09-15T10:29:51Z

What is a proper way of doing a substraction with datetime

1 Answers1