I think that having these keymaps set by default is a mistake; but more relevant to your question, here is another question: what is the problem with the present situation, which seems to accept either a string or a list of strings?

Consider the situation that I encountered. I wanted to remove some keys from the default keymap so that I could use them for myself in my own app. So my code originally looped through the keymaps and popped any keys I was using from the lists. But, if a keymap was a string, not a list of strings, then you obviously can't pop it.

Another situation would be some sort of check that some key was in a particular map:

> rcParam['keymap.foo']
'right'
> event.key
'h'
> event.key in rcParam['keymap.foo']
True

However, if rcParam['keymap.foo'] = ['right'], as it should be, then the above boolean would act as expected.

@WeatherGod, if you are motivated, a PR for 1.4.x that forces validation, together with whatever documentation is needed to make it clear that a keymap will end up always as a list of strings, seems reasonable to me. If your opinion has changed, then this can be closed.

@WeatherGod: Sorry to get to this so late, but I agree with @efiring: If it's feasible to validate all the entries and make things consistent, I think that would be nice. An easier as less likely to break things option might be to just change the defaults to be lists.

This is addressed by #3564