trie using dict in python

trie2.py

N = int(input())
d = {}
for _ in range(N):
    cmd = input().strip().split()
    if cmd[0] == 'add':
        s = cmd[1]
        for i in range(len(s)):
            prefix = s[:i+1]
            d[prefix] = d.get(prefix, 0) + 1
    elif cmd[0] == 'find':
        s = cmd[1]
        print(str(d.get(s, 0)))