How can I account for period (AM/PM) with datetime.strptime?

问题

Specifically I have code that simplifies to this:

from datetime import datetime
date_string = \'2009-11-29 03:17 PM\'
format = \'%Y-%m-%d %H:%M %p\'
my_date = datetime.strptime(date_string, format)

# This prints \'2009-11-29 03:17 AM\'
print my_date.strftime(format)

What gives? Does Python just ignore the period specifier when parsing dates or am I doing something stupid?

回答1:

The Python time.strftime docs say:

When used with the strptime() function, the %p directive only affects the output hour field if the %I directive is used to parse the hour.

Sure enough, changing your %H to %I makes it work.

回答2:

format = '%Y-%m-%d %H:%M %p'

The format is using %H instead of %I. Since %H is the "24-hour" format, it's likely just discarding the %p information. It works just fine if you change the %H to %I.

回答3:

You used %H (24 hour format) instead of %I (12 hour format).

回答4:

Try replacing %H (Hour on a 24-hour clock) with %I (Hour on a 12-hour clock) ?

来源：https://stackoverflow.com/questions/1759455/how-can-i-account-for-period-am-pm-with-datetime-strptime