Python练习一

1.使用while循环输入1 2 3 4 5 6 8 9 10

s = 0
while s < 10:
    s = s + 1
    if s == 7:
        continue
    print(s)
    

2.求1-100的所有数和

s = 1
sum = 0
while s <= 100:
    sum = sum + s
    s = s + 1
print(sum)

3.输出1-100内的所有奇数

a = 1
s = 2
while a <= 100:
    if a % 2 == 1:
        print(a)
    a = a + 1

4.输出1-100内的所有偶数

a = 1
s = 2
while a <= 100:
    if a % 2 == 0:
        print(a)
    a = a + 1

5.求1-2+3-4+...99的所有数的和

a = 1
b = 1
s = 2
sum1 = 0
sum2 = 0
while a <= 100:
    if a % 2 == 1:
        sum1 = sum1 + a
    a = a + 1
while b < 100:
    if b % 2 == 0:
        sum2 = sum2 + b
    b = b + 1
sum3 = sum1 - sum2
print(sum3)

6.用户登录（三次机会重试)

count = 1
while count <= 3:
　　user = input("请输入您的用户名:")
　　password = input("请输入您的密码:")
　　if user == "lin" and password == "110120":
　　　　print("登录成功")
　　　　break
　　else:
　　　　print("用户名或密码错误，请重新输入")
　　count = count + 1