How to convert Python's .isoformat() string back into datetime object [duplicate]

So in Python 3, you can generate an ISO 8601 date with .isoformat(), but you can't convert a string created by isoformat() back into a datetime object because Python's own datetime directives don't match properly. That is, %z = 0500 instead of 05:00 (which is produced by .isoformat()).

For example:

>>> strDate = d.isoformat() >>> strDate '2015-02-04T20:55:08.914461+00:00' >>> objDate = datetime.strptime(strDate,"%Y-%m-%dT%H:%M:%S.%f%z") Traceback (most recent call last): File "<stdin>", line 1, in <module> File "C:\Python34\Lib\_strptime.py", line 500, in _strptime_datetime tt, fraction = _strptime(data_string, format) File "C:\Python34\Lib\_strptime.py", line 337, in _strptime (data_string, format)) ValueError: time data '2015-02-04T20:55:08.914461+00:00' does not match format '%Y-%m-%dT%H:%M:%S.%f%z' 

From Python's strptime documentation: ()

%z UTC offset in the form +HHMM or -HHMM (empty string if the the object is naive). (empty), +0000, -0400, +1030

So, in short, Python does not even adhere to its own string formatting directives.

I know datetime is already terrible in Python, but this really goes beyond unreasonable into the land of plain stupidity.

Tell me this isn't true.

2 Answers

Python 3.7+

As of Python 3.7 there is a method datetime.fromisoformat() which is exactly the reverse for isoformat().

Older Python

If you have older Python, then this is the current best "solution" to this question:

pip install python-dateutil 

Then...

import datetime import dateutil def getDateTimeFromISO8601String(s): d = dateutil.parser.parse(s) return d 

Try this:

>>> def gt(dt_str): ... dt, _, us = dt_str.partition(".") ... dt = datetime.datetime.strptime(dt, "%Y-%m-%dT%H:%M:%S") ... us = int(us.rstrip("Z"), 10) ... return dt + datetime.timedelta(microseconds=us) 

Usage:

>>> gt("2008-08-12T12:20:30.656234Z") datetime.datetime(2008, 8, 12, 12, 20, 30, 656234)