python 矩阵转置 transpose

def transpose1(matrix):
    cols = len(matrix[0])
    return [[row[i] for row in matrix] for i in range(0,cols)]


def transpose2(matrix):
    transposed = []
    for i in range(len(matrix[0])):
        transposed.append([row[i] for row in matrix])
    return transposed


def transpose3(matrix):
    transposed = []
    for i in range(len(matrix[0])):
        transposed_row = []
        for row in matrix:
            transposed_row.append(row[i])
        transposed.append(transposed_row)
    return transposed

matrix = [
    [1,2,3,4],
    [5,6,7,8],
    [9,10,11,12]
]
print(transpose1(matrix))
print(transpose2(matrix))
print(transpose3(matrix))