Question

尝试进行交错，但因为我是初学者而遇到麻烦。它假设在测试时交错整数集，但我只是不断收到一条错误消息，说明＆＃34;索引超出范围＆＃34;。

def interleave(nums):
    new_nums = []
    index = 0
    if len(nums) == 0:
        return new_nums
    for j in range(len(nums)):
        for i in range(len(nums[0])):
            new_nums.append(nums[j][index])
            index += 1
    return new_nums

并使用以下值进行测试：

print("Testing interleave() for nums = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]: " + str(
    interleave([[1, 2, 3], [4, 5, 6], [7, 8, 9]])))

预期结果是：

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

使用这两个值进行测试时：

print("Testing interleave() for nums = [[0, 1, 0], [1, 0, 0], [0, 0, 1]]: " + str(
    interleave([[0, 1, 0], [1, 0, 0], [0, 0, 1]])))  
print("Testing interleave() for nums = [[1, 2], [3, 4], [5, 6], [7, 8], [9, 0]]: " + str(
    interleave([[1, 2], [3, 4], [5, 6], [7, 8], [9, 0]])))

预期结果应为：

[0, 1, 0, 1, 0, 0, 0, 0, 1] 
[1, 3, 5, 7, 9, 2, 4, 6, 8, 0]

但是我得到一个IndexError：list index超出范围

Answer 1

简单修复您的功能

def interleave(nums):
    new_nums = []
    index = 0
    if len(nums) == 0:
        return new_nums
    for j in range(len(nums)):
        for i in range(len(nums[0])):
            new_nums.append(nums[i][index])
        index += 1
    return new_nums


print("Testing interleave() for nums = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]: " + str(
    interleave([[1, 2, 3], [4, 5, 6], [7, 8, 9]])))

您可以使用j而不是索引 - 不需要索引

基本上，你要做的是转置二维数组和ravel（concat）使用numpy

参见下面的最后一行

import numpy as np
def interleave(nums):
    new_nums = []
    if len(nums) == 0:
        return new_nums
    for j in range(len(nums)):
        for i in range(len(nums[0])):
            new_nums.append(nums[i][j])
    return new_nums


print("Testing interleave() for nums = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]: " + str(
    interleave([[1, 2, 3], [4, 5, 6], [7, 8, 9]])))

print ("Testing interleave() for nums = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]: ", list(np.ravel(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]).transpose())))

Answer 2

此处的问题是index永远不会重置，因此您获得的最大值为index，这是您拥有的元组数量。

如果你反过来说，你可能会发现它更容易，首先你循环遍历单个元组元素，然后遍历元组列表。这样你也可以摆脱index：

def interleave(nums):
    new_nums = []
    if len(nums) == 0:
        return new_nums
    for j in range(len(nums[0])):
        for i in range(len(nums)):
            new_nums.append(nums[i][j])
    return new_nums

print("Testing interleave() for nums = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]: " + str(
    interleave([[1, 2, 3], [4, 5, 6], [7, 8, 9]])))

这种交错代码不起作用

2 个答案: