Python 在脚本中转置矩阵时出现索引错误
我有一个转置平方矩阵的程序:Python 在脚本中转置矩阵时出现索引错误,python,list,matrix,Python,List,Matrix,我有一个转置平方矩阵的程序: matrix = [[1, 2, 4], [3, 6, 9], [6, 8, 2]] matrix _trans = [] for i in range (len (matrix)): for j in range (len (matrix)): matrix_trans [j] [i] = matrix [i] [j] 错误: 索引器错误:列表索引超出范围 为什么会在此处产生此错误?问题在于matrix\u trans只是一个空列
matrix = [[1, 2, 4], [3, 6, 9], [6, 8, 2]]
matrix _trans = []
for i in range (len (matrix)):
for j in range (len (matrix)):
matrix_trans [j] [i] = matrix [i] [j]
错误:
索引器错误:列表索引超出范围
为什么会在此处产生此错误?问题在于
matrix\u trans
只是一个空列表,这就是为什么您无法访问任何indx,请创建matrix
的副本:
matrix = [[1, 2, 4], [3, 6, 9], [6, 8, 2]]
matrix_trans = [x[:] for x in matrix]
这是因为
matrix\u trans[j][i]
,在第一次迭代中j
和i
都将为零,matrix\u trans
是一个空列表,因此matrix\u trans[0]
将引发索引错误,您应该在strat中有第一个矩阵的维度的副本,如下所示:
from copy import deepcopy
matrix = [[1, 2, 4], [3, 6, 9], [6, 8, 2]]
matrix_trans = deepcopy(matrix)
for i in range(len(matrix)):
for j in range(len(matrix)):
matrix_trans[j][i] = matrix[i][j]
list(zip(*matrix))
结果:
In [41]: matrix_trans
Out[41]: [[1, 3, 6], [2, 6, 8], [4, 9, 2]]
In [42]: matrix
Out[42]: [[1, 2, 4], [3, 6, 9], [6, 8, 2]]
有关复制
模块的更多信息,请阅读
另外,请注意,对于此操作,您可以使用Pythonzip
。像这样:
from copy import deepcopy
matrix = [[1, 2, 4], [3, 6, 9], [6, 8, 2]]
matrix_trans = deepcopy(matrix)
for i in range(len(matrix)):
for j in range(len(matrix)):
matrix_trans[j][i] = matrix[i][j]
list(zip(*matrix))