map/reduce 函数式编程 high 到不行。
>> import operator
>> A = [[1], [2, 3], [4, 5, 6]]
>> reduce(operator.add, map(len, A))
6
map/reduce 函数式编程 high 到不行。
>> import operator
>> A = [[1], [2, 3], [4, 5, 6]]
>> reduce(operator.add, map(len, A))
6