循环

for …in…

names = ['Michael', 'Bob', 'Tracy']
for name in names:
    print(name)

for x in [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]:
    sum = sum + x

for x in range(101):
    sum = sum + x

while循环

while n > 0:
    sum = sum + n
    n = n - 2

break的作用是提前结束循环。
continue的作用是提前结束本轮循环，并直接开始下一轮循环。
不要滥用break和continue语句。