並行，使用zip函數。
l1=['1','2','3','4','5']
l2=['a','b','c','d','e']
l3=['qqq','www','eee','rrr','ttt']
l4=zip(l1,l2,l3)
for x,y,z in l4:
print(x,y,z)
print(list(zip(l1,l2,l3))) #[('1', 'a', 'qqq'), ('2', 'b', 'www'), ('3', 'c', 'eee'), ('4', 'd', 'rrr'), ('5', 'e', 'ttt')]
串行：使用itertools下的chain函數
from itertools import chain
l1=['1','2','3','4','5']
l2=['a','b','c','d','e']
l3=['qqq','www','eee','rrr','ttt']
l4=chain(l1,l2,l3)
for x in l4:
print(x)
print(list(chain(l1,l2,l3))) #['1', '2', '3', '4', '5', 'a', 'b', 'c', 'd', 'e', 'qqq', 'www', 'eee', 'rrr', 'ttt']