How to generate UK postcode using Faker or by own function in Python?

I am kind of a newbie in Python and was wondering how can I generate UK postcode using faker. I was reading the documentation but didn't really understand how to do that. Please read more about faker in here.

Alternatively, I would like to make my own UK postcode generator. The format is generally AB12 1AB. Some more UK postcode example can be seen in the picture.