for

myStr = 'abc'
for v in myStr:
    print(v)
for v in range(3):
    print(v)
for v in range(1,3):
    print(v)
# 输出
a
b
c
0
1
2
1
2

while

num = 5
while True:
    if num > 10:
        break
    print(num)
    num = num+1
# 输出
5
6
7
8
9
10

• continue