python - 在不使用预定义库的情况下生成集合的幂集？

Question

我正在尝试生成列表的幂集，而不使用任何库。例如，鉴于set {1, 2, 3},它应该返回{{}, {1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}, {1, 2, 3}}

注意：我们也可以使用 list 。

我已经实现了代码，但它不是动态的，它是针对特定长度的。我怎样才能使它动态。

代码：

my_list = [0, 1, 2, 3]

first_list = []
second_list = [[]]
final_list = []

for iterate in my_list:
    second_list.append([iterate])
    
for outer_loop in my_list:
    for inner_loop in my_list:
        if outer_loop!=inner_loop:
            first_list.append([outer_loop, inner_loop])
            
result = (second_list + first_list)

for iterated in result:
    if sorted(iterated) not in final_list:
        final_list.append(iterated)
final_list + [my_list]

标签： pythonlistset

Answer 1

尝试这个：

def get_powerset(s):
    x = len(s)
    subsets = []
    for i in range(1 << x):
        subsets.append([s[j] for j in range(x) if (i & (1 << j))])

    return subsets

lists = [[1, 2, 3], [0, 1, 2, 3]]
for num_list in lists:
    print(get_powerset(num_list))

输出：

[[], [1], [2], [1, 2], [3], [1, 3], [2, 3], [1, 2, 3]]
[[], [0], [1], [0, 1], [2], [0, 2], [1, 2], [0, 1, 2], [3], [0, 3], [1, 3], [0, 1, 3], [2, 3], [0, 2, 3], [1, 2, 3], [0, 1, 2, 3]]