在不删除元组的情况下展平列表

Question

如何在不删除元组的情况下展平包含元组的嵌套列表？例子：flatten([1,2,3,(4,5,6),[7,8,9]]) [1, 2, 3, (4, 5, 6),7,8,9]

Answer 1

为什么不是简单的循环：

>>> L = [1,2,3,(4,5,6),[7,8,9]]

>>> L2 = []

>>> for i in L:

    if isinstance(i,list):

        L2.extend(i)

    else:

        L2.append(i)

>>> L2

[1, 2, 3, (4, 5, 6), 7, 8, 9]

>>> 

Answer 2

def flatten(arr):

    if not isinstance(arr, list):

        return arr

    else:

        output = []

        for sy in arr:

            if isinstance(sy, list):

                temp = flatten(sy)

                for py in temp:

                    output.append(py)

            else:

                output.append(sy)

        return output

print (flatten([1,2,3,(4,5,6),[7,8,9]]))

#[1, 2, 3, (4, 5, 6), 7, 8, 9]

Answer 3

试试看：

f = lambda *n: (e for a in n

    for e in (f(*a) if isinstance(a, (list)) else (a,)))

print(list(f([1,2,3,(4,5,6),[7,8,9]])))

# [1, 2, 3, (4, 5, 6), 7, 8, 9]