Python Cookbook

Module: Parsing a String into a Date/Time Object Portably

Credit: Brett Cannon

Python’s time module supplies the parsing function strptime only on some platforms, and not on Windows. Example 17-2 shows a strptime function that is a pure Python implementation of the time.strptime function that comes with Python. It is similar to how time.strptime is documented in the standard Python documentation. It accepts two more optional arguments, as shown in the following signature:

strptime(string, format="%a %b %d %H:%M:%S %Y", option=AS_IS, locale_setting=ENGLISH)

option’s default value of AS_IS gets time information from the string, without any checking or filling-in. You can pass option as CHECK, so that the function makes sure that whatever information it gets is within reasonable ranges (raising an exception otherwise), or FILL_IN (like CHECK, but also tries to fill in any missing information that can be computed). locale_setting accepts a locale tuple (as created by LocaleAssembly) to specify names of days, months, and so on. Currently, ENGLISH and SWEDISH locale tuples are built into this recipe’s strptime module.

Although this recipe’s strptime cannot be as fast as the version in the standard Python library, that’s hardly ever a major consideration for typical strptime use. This recipe does offer two substantial advantages. It runs on any platform supporting Python and gives perfectly identical results on different platforms, while time.strptime exists only on some platforms and tends ...