Converting string into datetime

I've got a huge list of date-times like this as strings:

Jun 1 2005  1:33PM
Aug 28 1999 12:00AM

I'm going to be shoving these back into proper datetime fields in a database so I need to magic them into real datetime objects.

This is going through Django's ORM so I can't use SQL to do the conversion on insert.

Solution 1:

datetime.strptime is the main routine for parsing strings into datetimes. It can handle all sorts of formats, with the format determined by a format string you give it:

from datetime import datetime

datetime_object = datetime.strptime('Jun 1 2005  1:33PM', '%b %d %Y %I:%M%p')

The resulting datetime object is timezone-naive.

Links:

• Python documentation for strptime: Python 2, Python 3

• Python documentation for strptime/strftime format strings: Python 2, Python 3

• strftime.org is also a really nice reference for strftime

Notes:

• strptime = "string parse time"
• strftime = "string format time"
• Pronounce it out loud today & you won't have to search for it again in 6 months.

Also, as seen in a comment made by @Izkata, if you want a date instead of a datetime, going through datetime handles it nicely: datetime.strptime('Jun 1 2005', '%b %d %Y').date() == date(2005, 6, 1)

Solution 2:

Use the third party dateutil library:

from dateutil import parser
parser.parse("Aug 28 1999 12:00AM")  # datetime.datetime(1999, 8, 28, 0, 0)

It can handle most date formats, including the one you need to parse. It's more convenient than strptime as it can guess the correct format most of the time.

It's very useful for writing tests, where readability is more important than performance.

You can install it with:

pip install python-dateutil

Solution 3:

Check out strptime in the time module. It is the inverse of strftime.

$ python
>>> import time
>>> my_time = time.strptime('Jun 1 2005  1:33PM', '%b %d %Y %I:%M%p')
time.struct_time(tm_year=2005, tm_mon=6, tm_mday=1,
                 tm_hour=13, tm_min=33, tm_sec=0,
                 tm_wday=2, tm_yday=152, tm_isdst=-1)

timestamp = time.mktime(my_time)
# convert time object to datetime
from datetime import datetime
my_datetime = datetime.fromtimestamp(timestamp)
# convert time object to date
from datetime import date
my_date = date.fromtimestamp(timestamp)