import random
def get_code(num=5):
lis1 = ['1','2','3','4','5','6','7','8','9']
for i in range(65, 90):
lis1.append(chr(i))
for i in range(97, 122):
lis1.append(chr(i))
l2 = random.sample(lis1,num)
return ''.join(l2)
