Trie is probably my favourite ds. I really enjoy this python implementation I learned while studying leetcode because its so succint. Really useful for interviews.

    from collections import defaultdict
    
    END = object()

    def make_trie():
       return defaultdict(make_trie)
    
    def insert(trie, word):
        for c in word:
            trie = trie[c]
        trie[END] = True