How to compare dates in Python?

问题

I need to see if a date has more than X days. How can I do this in Python?

I have tested something like:

if datetime.date(2010, 1, 12) > datetime.timedelta(3):

I got the error:

TypeError: can't compare datetime.date to datetime.timedelta

Any clue on how to achieve this?

回答1:

You can't compare a datetime to a timedelta. A timedelta represents a duration, a datetime represents a specific point in time. The difference of two datetimes is a timedelta. Datetimes are comparable with each other, as are timedeltas.

You have 2 options:

• Subtract another datetime from the one you've given, and compare the resulting timedelta with the timedelta you've also given.
• Convert the timedelta to a datetime by adding or subtracting it to another datetime, and then compare the resulting datetime with the datetime you've given.

回答2:

Comparing apples and oranges is always very hard! You are trying to compare "January 12, 2010" (a fixed point in time) with "3 hours" (a duration). There is no sense in this.

If what you are asking is "does my datetime fall after the nth day of the month" then you can do :

my_important_date = datetime.now()

if my_important_date.day > n:
    pass #do you important things

来源：https://stackoverflow.com/questions/7873013/how-to-compare-dates-in-python