How to get the last day of the month?

Question

Is there a way using Python's standard library to easily determine (i.e. one function call) the last day of a given month?

If the standard library doesn't support that, does the dateutil package support this?

Answer 1

I didn't notice this earlier when I was looking at the documentation for the calendar module, but a method called monthrange provides this information:

monthrange(year, month)
    Returns weekday of first day of the month and number of days in month, for the specified year and month.

>>> import calendar
>>> calendar.monthrange(2002,1)
(1, 31)
>>> calendar.monthrange(2008,2)
(4, 29)
>>> calendar.monthrange(2100,2)
(0, 28)

so:

calendar.monthrange(year, month)[1]

seems like the simplest way to go.

Just to be clear, monthrange supports leap years as well:

>>> from calendar import monthrange
>>> monthrange(2012, 2)
(2, 29)

My previous answer still works, but is clearly suboptimal.