I thought it would be weird to allow it to be non-int since the current Trie type only allows int values.

I'd be happy to change it if you want to allow storing arbitrary types in the Trie. I actually mentioned this as a desirable feature in #7. If you go ahead and merge this PR, I'd be happy to work towards getting full non-int functionality in a separate PR; although, I may need a little help as I'm not that familiar with Cython.