1

If I print a datetime object in python with a simple print myDateTime (or print(myDateTime) in python3), how can I recover the datetime object from the resulting string?

I could have asked "what is the python strftime format used by datetime.__str__()"?

ps: There are many questions about conversion of strings to python datetime objects. In the spirit of using stack overflow as a repository of quickly available, useful programming tips, I'm asking this since none of those questions answer this rather specific and oft needed query.

user2864740
  • 60,010
  • 15
  • 145
  • 220
drevicko
  • 14,382
  • 15
  • 75
  • 97

2 Answers2

2

By definition, str(datetime_obj) is datetime_obj.isoformat(' '). There is no method that would parse the ISO 8601 format back; you have to provide the format to strptime() explicitly:

>>> from datetime import datetime, timezone
>>> now = datetime.now(timezone.utc)
>>> s = str(now)
>>> s
'2015-04-06 10:31:08.256426+00:00'
>>> s[:26]
'2015-04-06 10:31:08.256426'
>>> datetime.strptime(s[:26]+s[26:].replace(':',''), '%Y-%m-%d %H:%M:%S.%f%z')
datetime.datetime(2015, 4, 6, 10, 31, 8, 256426, tzinfo=datetime.timezone.utc)

%z supports +HHMM but it doesn't support +HH:MM that is why the replace() call is used here.

datetime.timezone is available since Python 3.2. For older versions, see

Community
  • 1
  • 1
jfs
  • 399,953
  • 195
  • 994
  • 1,670
1

If the datetime object doesn't have timezone info (perhaps interpreted as UTC time), you can do something like this (python 2 in this case, but the same in python 3):

import datetime
unprintStrptimeFmt = "%Y-%m-%d %H:%M:%S.%f"
d = datetime.datetime.utcnow()
print d
# produces e.g.: 2015-04-06 03:11:23.840526
dd = datetime.datetime.strptime("2015-04-06 03:11:23.840526",unprintStrptimeFmt)
print dd == d 
# produces: True
drevicko
  • 14,382
  • 15
  • 75
  • 97