Python -遍历和修改2d数组不起作用

# 创建一个2D数组
array = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

# 遍历和修改2D数组
for i in range(len(array)):
    for j in range(len(array[i])):
        # 修改数组元素
        array[i][j] *= 2

# 打印修改后的2D数组
print(array)

[[2, 4, 6], [8, 10, 12], [14, 16, 18]]

# 创建一个2D数组
array = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

# 使用列表推导式遍历和修改2D数组
array = [[element * 2 for element in row] for row in array]

# 打印修改后的2D数组
print(array)

[[2, 4, 6], [8, 10, 12], [14, 16, 18]]

import numpy as np

# 创建一个2D数组
array = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

# 遍历和修改2D数组
for i in range(array.shape[0]):
    for j in range(array.shape[1]):
        # 修改数组元素
        array[i][j] *= 2

# 打印修改后的2D数组
print(array)

[[ 2  4  6]
 [ 8 10 12]
 [14 16 18]]