while 循环

一、使用while循环输入 1 2 3 4 5 6 7 8 9 10

count = 1
while count < 11:
    if count == 7:
        count += 1
        continue
    print(count)
    count +=1
else:print("end")

二、求1-100的所有数的和

count = 1
sum = 0
while count < 101:
    sum = sum + count
    count += 1
print(sum)


三、输出1-100内的所有奇数

count = 1
while count < 101:
    if count %2 == 1:
        print(count)
    count += 1
print("end")


四、输出1-100内所有偶数

count = 1
while count < 101:
    if count %2 ==0:
        print(count)
    count += 1
print("end")


五、求1-2+3-4+5....99的所有数的和

#方法一

sum = 0 
count = 1
while count < 100:
    if count %2 == 0:
        sum = sum - count
        print(sum)
    elif count %2 == 1:
        sum = count + sum
        print(sum)
    count += 1
print(sum)


方法二

sum1 = 0
sum2 = 0
count = 1
while count < 100:
    if count %2 == 1:
        sum1 = sum1 + count
    else:
        sum2 = sum2 + count
    count += 1
print(sum1 - sum2)

#六、用户登陆（三次机会重试）
count = 1
while count < 4:
    name = input("please input your name=")
    password = input("please input your password=")
    if name == "xue" and password == "123":
        print("login successful")
        break
    else:
        print("login failed")
    count += 1
print("end")