count = 1
result = 0
计算1-100
while count <= 100:
result += count
count += 1
print(result)



while count <= 100:
result = result + count
count = count + 1
print(result)

while True:
result += count
if count > 100:
break
count += 1
print(result)

while count <= 100:
count += 1
if count == 80:
print("count 等于 %d 跳""出本次循环" % count)
continue
print(count)


1. 使用while 循环输入1 2 3 4 5 6 8 9 10
count = 0
while count < 10:
count += 1
if count == 7:
continue
print("%d" % count)

2. 求1-100的所有奇数

count = 0
while count < 100:
count += 1
if count % 2 != 0:
# print("odd number:%d" % count)
result += count
else:
print("1~100偶数之和: %d" % result)


3. 求1-100的所有偶数

count = 0
result = 0
while count < 100:
count += 1
if count % 2 == 0:
# print("even number: %d " % count)
result += count
else:
print("1~100 奇数之和%d" % result)

result = 0
counter = 0

while counter < 100:
counter += 1
# 奇数
if counter % 2 == 1:
continue
# 偶数
else:
result += counter
print(result)



4.用1-2+3-4+5...99的所有数的和


count = 1
result = 0
while count < 100:
# 偶数
if count % 2 == 0:
result -= count
# 奇数
else:
result += count
count += 1
# print(count)

print(result)

5.用户登陆(三次机会重试)

count = 1
while count <= 3:
count += 1
user_name = input("请输入你的用户名:")
else:
print("输入错误超过3次,请稍后再试")

username = "admin"
passwd = "123456"

count = 1
while count <= 3:
count += 1
username = input("请输入你的用户名:")
passwd = input("请输入你的米码:")
if username == "admin" and passwd == "123456":
print("登陆成功")
break
else:
print("登陆失败,请再试")



username = "admin"
passwd = "123456"

count = 1
while count <= 3:
count += 1
username = input("请输入你的用户名:")
passwd = int(input("请输入你的米码:"))
if username == "admin" and passwd == 123456:
print("登陆成功")
break
else:
print("登陆失败,请再试")



先定义计数器
while 条件
count += 1 #计数器 + 1
执行语句
else:
上次正常执行完成后,再执行语句




# while语句支持else语句
# else语句只在循环完成后执行
# 如果循环是被break中断掉的话,else也会被跳过
import random

guess = 1
computer = random.randint(1, 100)
while guess < 5:

num = int(input("请输入你猜的数字:"))
# 猜对处理并退出
if guess == computer:
print("你猜对了,你猜的是%s" % num)
break
elif guess < computer:
print("你猜小了,你猜的是%s" % num)
else:
print("你猜大了,你猜的是%s" % num)
guess += 1
else:
print("电脑随机数是%s" % str(computer))