Getting indices of True values in a boolean list

Question

I have a piece of my code where I\'m supposed to create a switchboard. I want to return a list of all the switches that are on. Here \"on\" will equal True and

Answer 1

You can use filter for it:

filter(lambda x: self.states[x], range(len(self.states)))

The range here enumerates elements of your list and since we want only those where self.states is True, we are applying a filter based on this condition.

For Python > 3.0:

list(filter(lambda x: self.states[x], range(len(self.states))))