Question

I have a system (developed in Python) that accepts datetime as string in VARIOUS formats and i have to parse them..Currently datetime string formats are :

Fri Sep 25 18:09:49 -0500 2009

2008-06-29T00:42:18.000Z

2011-07-16T21:46:39Z

1294989360

Now i want a generic parser that can convert any of these datetime formats in appropriate datetime object…

Otherwise, i have to go with parsing them individually. So please also provide method for parsing them individually (if there is no generic parser)..!!

Answer 1

As @TimPietzcker suggested, the dateutil package is the way to go, it handles the first 3 formats correctly and automatically:

>>> from dateutil.parser import parse
>>> parse("Fri Sep 25 18:09:49 -0500 2009")
datetime.datetime(2009, 9, 25, 18, 9, 49, tzinfo=tzoffset(None, -18000))
>>> parse("2008-06-29T00:42:18.000Z")
datetime.datetime(2008, 6, 29, 0, 42, 18, tzinfo=tzutc())
>>> parse("2011-07-16T21:46:39Z")
datetime.datetime(2011, 7, 16, 21, 46, 39, tzinfo=tzutc())

The unixtime format it seems to hiccough on, but luckily the standard datetime.datetime is up for the task:

>>> from datetime import datetime
>>> datetime.utcfromtimestamp(float("1294989360"))
datetime.datetime(2011, 1, 14, 7, 16)

It is rather easy to make a function out of this that handles all 4 formats:

from dateutil.parser import parse
from datetime import datetime

def parse_time(s):
    try:
        ret = parse(s)
    except ValueError:
        ret = datetime.utcfromtimestamp(s)
    return ret