practice python.org practice#5 (since there is no solution)

import random
from random import randrange
a = []
for i in range(0, randrange(1, 20)):
    n = random.randint(1, 100)
    a.append(n)

b = []
for i in range(0, randrange(1, 20)):
    n = random.randint(1, 100)
    b.append(n)
print(a)
print(b)
my_list = []
for i in a and b:
    if i in a and b:
        my_list.append(i)
        if i in my_list:
            break
    if i not in a and b:
        pass
print my_list