在Python中,创建一个空的二维列表可以通过以下几种方法:
1. 使用嵌套的列表推导式:
rows = 3
cols = 4
matrix = [[0 for _ in range(cols)] for _ in range(rows)]
print(matrix)
输出:
[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]
2. 使用嵌套循环:
rows = 3
cols = 4
matrix = []
for _ in range(rows):
row = []
for _ in range(cols):
row.append(0)
matrix.append(row)
print(matrix)
输出:
[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]
3. 使用`numpy`库创建二维列表:
import numpy as np
rows = 3
cols = 4
matrix = np.zeros((rows, cols))
print(matrix)
输出:
[[0. 0. 0. 0.]
[0. 0. 0. 0.]
[0. 0. 0. 0.]]