随机排列 python 数组中的某些项目

Question

我需要打乱 python 数组的某些元素，这取决于第二个数组说明应该打乱哪些索引。最好就地。

arr = [1,2,3,4,5,6]
indeces_to_shuffle = [0,4,5]

shuffle_algorithm(arr, indeces_to_shuffle) # Need help here!

print(arr)
> 6,2,3,4,1,5

Answer 1

from random import shuffle


arr = [1,2,3,4,5,6]
indeces_to_shuffle = [0,4,5]

vals = [arr[i] for i in indeces_to_shuffle]
shuffle(indeces_to_shuffle)

for i, v  in zip(indeces_to_shuffle, vals):
    arr[i] = v

print(arr)

打印（例如）：

[5, 2, 3, 4, 6, 1]

Answer 2

数组还是列表？如果您使用的是数组，则可以这样做：

arr[indeces_to_shuffle] = np.random.permutation(arr[indeces_to_shuffle])

结果：

array([6, 2, 3, 4, 5, 1])

Answer 3

如果我没有正确理解你的问题，我可以建议下一步：

import random

lst = [1,2,3,4,5,6]
shuffle_index = (0,4,5)

def shuffled(lst, indexes):
    for i in indexes:
        swap_vars = [j for j in range(len(lst)) if j != i]
        swap_pos = random.choice(swap_vars)
        s1, s2 = lst[i], lst[swap_pos]
        lst[i], lst[swap_pos]  = s2, s1
    return lst

print(f'Original: {lst}')
print(f'Shuffled: {shuffled(lst, shuffle_index)}')

输出：

Original: [1, 2, 3, 4, 5, 6]
Shuffled: [6, 5, 3, 4, 1, 2]

随机排列 python 数组中的某些项目

Shuffle certain items in python array

python

shuffle

in-place