Transform Matrix 90 degrees

transform.py

from pprint import pprint as pp


def transpose(self, A: list[list[int]]) -> list[list[int]]:
    # using list comprehension
    return [[row[c] for row in A] for c in range(len(A[0]))]

def transpose(self, A: list[list[int]]) -> list[list[int]]:
    # using zip
    return [list(x) for x in zip(*A)]

def transpose(self, A: list[list[int]]) -> list[list[int]]:
    # pure manual implementation
    rows = len(A)
    cols = len(A[0])
    T = [[0] * rows for _ in range(cols)]
    for r in range(rows):
        for c in range(cols):
            T[c][r] = A[r][c]
    return T


# create a matrix
rows, cols = (5, 10)
data = [[j + cols * i for j in range(cols)] for i in range(rows)]

print("Data before transform")
pp(data)

data_t = transform(data)
print("Transformed data using loop")
pp(data_t)

data_t = [list(x) for x in zip(*data)]
print("Transformed data using zip")
pp(data_t)


"""
Data before transform
[[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
 [10, 11, 12, 13, 14, 15, 16, 17, 18, 19],
 [20, 21, 22, 23, 24, 25, 26, 27, 28, 29],
 [30, 31, 32, 33, 34, 35, 36, 37, 38, 39],
 [40, 41, 42, 43, 44, 45, 46, 47, 48, 49]]
 
Transformed data using loop
[[0, 10, 20, 30, 40],
 [1, 11, 21, 31, 41],
 [2, 12, 22, 32, 42],
 [3, 13, 23, 33, 43],
 [4, 14, 24, 34, 44],
 [5, 15, 25, 35, 45],
 [6, 16, 26, 36, 46],
 [7, 17, 27, 37, 47],
 [8, 18, 28, 38, 48],
 [9, 19, 29, 39, 49]]

Transformed data using zip
[[0, 10, 20, 30, 40],
 [1, 11, 21, 31, 41],
 [2, 12, 22, 32, 42],
 [3, 13, 23, 33, 43],
 [4, 14, 24, 34, 44],
 [5, 15, 25, 35, 45],
 [6, 16, 26, 36, 46],
 [7, 17, 27, 37, 47],
 [8, 18, 28, 38, 48],
 [9, 19, 29, 39, 49]]
"""