使用Python的groupby實現壓縮功能

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from itertools import groupby

def compress(data):
    return ((name, len(list(group))) for name, group in groupby(data))

def decompress(data):
    return (name * size for name, size in data)

c = compress('get uuuuuuuuuuuuuuuuuuuuuuuup')
print(''.join(decompress(c)))

 grouby函數類似Unix命令uniq，對相鄰的重複元素進行分組。

groupby(iterable[, keyfunc]) -> create an iterator which returns (key, sub-iterator) grouped by each value of key(value).

迭代sub-iterator得到的就是每一個元素，即key。