9. 循环
死循环
import time
while 1 == 1:
print('ok',time,time())
not死循环
import time
count = 0
while count < 10:
print(count)
count == count + 1
print(123)
补continue、break:
count = 0
while count < 10:
if count == 7:
count = count +1
continue # 不再向下执行,直接回到while继续进行循环
print(count)
count = count + 1
count = 0
while count < 10:
if count == 7:
break # 终止所有循环
print(count)
count = count + 1
练习题
if条件语句
while循环
奇数偶数
1、使用while循环输入1 2 3 4 5 6 8 9 10
n = 1
while n < 11:
if n == 7:
pass
else:
print(n)
n = n + 1
print('end')
2、求1 - 100的所有数的和
n = 1
s = 0
while n < 101:
s = s + n
n = n + 1
print(s)
3、输出1 - 100内所有的奇数
n = 1
while n < 101:
temp = n % 2
if temp == 0:
pass
else:
print(n)
n = n + 1
print('end')
4、输出1 - 100内所有的偶数
n = 1
while n < 101:
temp = n % 2
if temp == 0:
print(n)
else:
pass
n = n + 1
print('end')
5、求1-2+3-4+5...99的所有数的和
n = 1
s = 0 # s是之前所有数的和
while n < 100:
temp = n % 2
if temp == 0:
s = s - n
else:
s = s + n
n = n + 1
print(s)
6、用户登录(三次重试的机会)
n = 0
while n < 3:
inp == input('请输入密码:')
if inp == woaini:
print('登陆成功')
break
else:
n = n + 1
print('登录失败')