Python define calculated matrix transpose function

Define calculated matrix transpose function

1) use cycle transpose

matrix = [[1, 2, 3, 4],[5, 6, 7, 8],[9, 10, 11, 12]]

# 打印矩阵
def printMatrix(m):
    for ele in m:
        for e in ele:
            print('%3d' % e, end='')
        print('')

# 转置矩阵
def transformMatrix(m):
    rt = [[] for i in m[0]]    # m[0] 有几个元素，说明原矩阵有多少列。此处创建转置矩阵的行
    for ele in m:
        for i in range(len(ele)):
            # rt[i] 代表新矩阵的第 i 行
            # ele[i] 代表原矩阵当前行的第 i 列
            rt[i].append(ele[i])
    return rt

printmatrix(matrix)
print('-'*40)
printmatrix(transformMatrix(matrix))

  1  2  3  4
  5  6  7  8
  9 10 11 12
----------------------------------------
  1  5  9
  2  6 10
  3  7 11
  4  8 12

2) using the zip () function transpose

Description : the plurality of functions into a ZIP sequence: a first element of the plurality of sequences are combined into the first element, the second element of the plurality of sequences are combined into the second sequence ...

Analysis : the original matrix to do the reverse parameters collection

def transformMatrix(m):
    # 逆向参数收集，将矩阵中多个列表转换成多个参数，传给 zip
    return list(zip(*m))

printmatrix(matrix)
print('-'*40)
printmatrix(transformMatrix(matrix))

  1  2  3  4
  5  6  7  8
  9 10 11 12
----------------------------------------
  1  5  9
  2  6 10
  3  7 11
  4  8 12

3) using transposition module numpy

Description:

1. numpy module provides TRANSPOSE () function performs transposition, the return value of the function is a built-in type numpy: array
2. Calling array of tolist () method to convert array to list list

import numpy

def transformMatrix(m):
    
    return numpy.transpose(m).tolist()

printmatrix(matrix)
print('-'*40)
printmatrix(transformMatrix(matrix))

  1  2  3  4
  5  6  7  8
  9 10 11 12
----------------------------------------
  1  5  9
  2  6 10
  3  7 11
  4  8 12