wanghq wanghq - 2 months ago 16
Python Question

Why %z is not supported by python's strptime?

>>> datetime.strptime('2014-02-13 11:55:00 -0800', '%Y-%m-%d %H:%M:%S %z')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/", line 317, in _strptime
(bad_directive, format))
ValueError: 'z' is a bad directive in format '%Y-%m-%d %H:%M:%S %z'

I understand that it's not supported, but don't know why. Seems it's not hard to support that. And 'Offset from UTC' is not as ambiguous as timezone abbreviation.


Until Python 3.2, Python's datetime module had no timezone() object. It supported 3rd-party libraries providing timezones by providing a datetime.tzinfo() abstract base class, but no timezone object was included. Without a timezone object, no support for parsing timezone offsets either.

As of Python 3.2, z is supported, because that version (and up) added a datetime.timezone() type:

>>> import datetime
>>> datetime.datetime.strptime('2014-02-13 11:55:00 -0800', '%Y-%m-%d %H:%M:%S %z')
datetime.datetime(2014, 2, 13, 11, 55, tzinfo=datetime.timezone(datetime.timedelta(-1, 57600)))
>>> _.tzinfo
datetime.timezone(datetime.timedelta(-1, 57600))