defaultdict 用法 python3

from collections import defaultdict


def test():
    d = defaultdict()
    s = [('yellow', 3), ('blue', 4), ('red', 1)]
    d = defaultdict(list)
    for k, v in s: 
        d[k].append(v)
    print(sorted(d.items()))
    pass

if __name__ == "__main__":
    print('*'*80)
    test()