Вывести элементы матрицы в следующем порядке: первый столбец сверху вниз, второй столбец снизу вверх

from random import randint
 
n, m = map(int, input().split())
arr = [[randint(0, 20) for _ in range(m)] for _ in range(n)]
print(*arr, sep='\n', end='\n\n')
 
for i in range(m):
    k = (0, -1)[i % 2]
    for _ in range(n):
        print(arr[k][i])
        k += (1, -1)[i % 2]
    print()

from random import randint
 
n, m = map(int, input().split())
arr = [[randint(0, 20) for _ in range(m)] for _ in range(n)]
print(*arr, sep='\n', end='\n\n')
 
for i in range(len(s := list(zip(*arr)))):
    if i % 2:
        print(*s[i][::-1])
    else:
        print(*s[i])

import random
import numpy
M = random.randrange(2,10)
N = random.randrange(2,10)
print("M = ",M,"; N = ",N)
a = numpy.zeros((M, N))
k = 0
for i in range(M):
    for j in range(N):
        k += 1
        a[i][j] = k
print(a)
for i in range(M):
    for j in range(N):
        if j%2 == 0:
            print(a[i][j],end=" ")
        else:
            print(a[M-1-i][j],end=" ")
    print()

from random import randint
m = randint(2, 10)
n = randint(2, 10)
print(f'M = {m}, N = {n}')
a = [[randint(0, 10) for _ in range(n)] for _ in range(m)]
for r in a:
    print(r)
tr=list(zip(*a))
for i in range(n):
    print(tr[i][::1 - (i % 2) * 2])