транспонирование

N = 4
a = [[(i*N + j + 1) for j in range(N)] for i in range(N)]

# распечатка:
for i in range(N):
    print(*a[i], sep='\t')
print()

# транспонирование:
for i in range(N-1):
    for j in range(i+1, N):
        a[i][j], a[j][i] = a[j][i], a[i][j]

# распечатка:
for i in range(N):
    print(*a[i], sep='\t')
print()