Word Embedding Lookup Index Bug

def lookup(word, word2idx, embeddings):
    idx = word2idx.get(word, 0)
    return embeddings[word]

vocab = {'cat': 1, 'dog': 2}
emb = [[0, 0], [0.2, 0.9], [0.5, 0.1]]
print(lookup('cat', vocab, emb))