1
2
3
4
5
6
7
8
9
10
matrix = [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]
[num for row in matrix for num in row]
# [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]

## transpose the matrix rows and columns
[[row[i] for row in matrix] for i in range(len(matrix[1]))]
# [[1, 5, 9], [2, 6, 10], [3, 7, 11], [4, 8, 12]]

list(zip(*matrix))
# [(1, 5, 9), (2, 6, 10), (3, 7, 11), (4, 8, 12)]