How to map month name to month number and vice versa?

Create a reverse dictionary using the calendar module (which, like any module, you will need to import):

{month: index for index, month in enumerate(calendar.month_abbr) if month}

In Python versions before 2.7, due to dict comprehension syntax not being supported in the language, you would have to do

dict((month, index) for index, month in enumerate(calendar.month_abbr) if month)