Python循环判断基础学习

使用while循环输入1 2 3 4 5 6  8 9 10

a = 1
while a < 11:
    if a == 7:
        pass
    else:
        print(a)
    a = a + 1

 

求1-100所有数的和

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

输出1-100所有偶数

a = 1
while a < 101:
    temp = a % 2
    if temp == 0:
        print(a)
    else:
        pass

求1-2+3-4+5...99的所有树的总和

a = 1
sum = 0
while a < 100:
    temp = a % 2
    if temp == 0:
        sum = sum - a
    else:
        sum = sum + a
    a = a + 1
print(sum)

python 判断三次登录密码错误

方法一：

passwd = "abcd1234"
huoqu = input("请输入核验身份密码：")
if huoqu == passwd:
    print("密码正确")
else:
    print("密码错误")
    huoqu = input("请重新输入：")
    if huoqu == passwd:
        print("密码正确")
    else:
        print("密码错误")
        huoqu = input("请重新输入：")
        if huoqu == passwd:
            print("密码正确")
        else:
            print("三次机会错误请重试")

方法二：

passwd = "abcd1234"
huoqu = input("请输入核验身份密码：")
srcs = 1

while srcs < 3:
    if huoqu == passwd:
        print("密码正确")
        srcs = 3
    else:
        print("密码错误")
        huoqu = input("请重新输入：")
        srcs = srcs + 1
        if srcs == 3:
            print("三次错误请重试")