Question

I am trying to perform some date arithmetic in a function.

from datetime import datetime, timedelta

def foo(date1, summing_period):
    current_period_start_date = date1 - timedelta(days=summing_period)
    # Line above causes the error:
    # TypeError: unsupported type for timedelta days component: datetime.datetime

First arg is a datetime obj and 2nd arg is an integer

What is causing this error, and how do I fix it?

Answer 1

summing_period should be an integer (representing the number of days), not a datetime object.

>>> timedelta(days=datetime.now())
TypeError: unsupported type for timedelta days component: datetime.datetime

>>> timedelta(days=5)
datetime.timedelta(5)