Patch datetime to use a much quicker strptime implementation.

This ONLY improves strptime when the format string uses padded directives.

This is the list of supported directives (by far the most common):

SUPPORTED_DIRECTIVES = ('%d', '%m', '%Y', '%H', '%M', '%S', '%f')

Check if your date/time format is supported by calling:

datetime.supported_strptime(format_string) # True if supported, False otherwise

On average, 4 times quicker than the stdlib version, and 40 times quicker when using pypy!

Usage:

# insert this one line from monkeytime import datetime # Done migrating code to monkeytime! from datetime import datetime # Call it once with the specific format string # It will build a new function to quickly parse the string, then run it on # the string you passed it. dt = datetime.strptime('2014-05-30T12:14:15.123456', '%Y-%m-%dT%H:%M:%S.%f') # Now, whenever you use that format again, it will use the function it # built already! All constructed functions are memoized. # Since we usually only use one or two formats in our code to parse logs # and such, the performance of constructing it is negligible.

All you need is that one line “from monkeytime import datetime”, and your strptime performance will increase dramatically.

Make sure it is ABOVE your “from datetime import datetime” import line!

Performance example:

$ python timeit_test.py Testing builtin strptime testing ('2015-01-02 03:04:05.001234', '%Y-%m-%d %H:%M:%S.%f') 6.80288290977 seconds testing ('05-06 12:15:18', '%m-%d %H:%M:%S') 5.81049013138 seconds testing ('2010', '%Y') 4.29107117653 seconds testing ('1905/08/05', '%Y/%m/%d') 4.92634987831 seconds testing ('14:05:03.123456', '%H:%M:%S.%f') 5.6812889576 seconds Testing monkeytime strptime testing ('2015-01-02 03:04:05.001234', '%Y-%m-%d %H:%M:%S.%f') 1.83126211166 seconds testing ('05-06 12:15:18', '%m-%d %H:%M:%S') 1.5586848259 seconds testing ('2010', '%Y') 0.877351999283 seconds testing ('1905/08/05', '%Y/%m/%d') 1.24154901505 seconds testing ('14:05:03.123456', '%H:%M:%S.%f') 1.3871409893 seconds 3.714860 times as fast 3.727816 times as fast 4.890935 times as fast 3.967906 times as fast 4.095682 times as fast Average: 4.079440 times as fast $ pypy timeit_test.py Testing builtin strptime testing ('2015-01-02 03:04:05.001234', '%Y-%m-%d %H:%M:%S.%f') 2.19319605827 seconds testing ('05-06 12:15:18', '%m-%d %H:%M:%S') 1.60669994354 seconds testing ('2010', '%Y') 0.858637809753 seconds testing ('1905/08/05', '%Y/%m/%d') 1.19449591637 seconds testing ('14:05:03.123456', '%H:%M:%S.%f') 1.38721394539 seconds Testing monkeytime strptime testing ('2015-01-02 03:04:05.001234', '%Y-%m-%d %H:%M:%S.%f') 0.0362730026245 seconds testing ('05-06 12:15:18', '%m-%d %H:%M:%S') 0.0450730323792 seconds testing ('2010', '%Y') 0.0332229137421 seconds testing ('1905/08/05', '%Y/%m/%d') 0.0321681499481 seconds testing ('14:05:03.123456', '%H:%M:%S.%f') 0.0355319976807 seconds 60.463593 times as fast 35.646591 times as fast 25.844747 times as fast 37.132876 times as fast 39.041260 times as fast Average: 39.625813 times as fast