Создайте массив 3, в состав которого поочередно входят элементы массива 1, а затем массива 2

from random import randint
n = int(input('n: '))
m1 = list(randint(1, 10) for _ in range(n))
m2 = list(randint(1, 10) for _ in range(n))
print(m1, m2, sep='\n')
m3 = m1 + m2
print(m3)

from random import randint
n = int(input('n: '))
print(m1 := list(randint(1, 10) for _ in range(n)), m2 := list(randint(1, 10) for _ in range(n)), m1 + m2, sep='\n')

from random import randint
n = int(input('n: '))
m1 = list(randint(1, 10) for _ in range(n))
m2 = list(randint(1, 10) for _ in range(n))
print(m1, m2, sep='\n')
m3 = []
for x, y in zip(m1, m2):
    m3.append(x)
    m3.append(y)
print(m3)

from random import randint
 
n = int(input('n: '))
m1 = list(randint(1, 10) for _ in range(n))
m2 = list(randint(1, 10) for _ in range(n))
print(m1, m2, sep='\n')
 
m3 = [None] * 2 * n
m3[::2], m3[1::2] = m1, m2
print(m3)

from random import randint
from itertools import chain
 
n = int(input('n: '))
m1 = [randint(1, 10) for _ in range(n)]
m2 = [randint(1, 10) for _ in range(n)]
*m3, = chain(*zip(m1, m2))
print(m1, m2, m3, sep='\n')

from functools import reduce
 
# просто печать
 
def foo(a1,a2):
    for pair in zip(a1,a2):
        print(*pair,end=' ')
 
# формирование массива
    
def bar(a1,a2):
    return reduce(lambda acc,x: acc+list(x),zip(a1,a2),[])
 
foo([1,2,3],[11,22,33])    
 
print(bar([1,2,3],[11,22,33]))