python条件循环语句

1、使用while循环输出1 2 3 4 5 6   8 9 10

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

2、输出1--100内所有奇数

 count = 1
 while count < 101:
     a = count % 2
     if a != 0:
         print(count)
     count = count + 1

3、输出1--100内所有偶数

 count = 1
 while count < 101:
     a = count % 2
     if a != 1:
         print(count)
     count = count + 1

4、求1--100所有数的和

n = 1
s = 0
while n < 101:
    s = s + n
    n = n + 1
    print(s)

5、求1-2+3-4+5 ... 999所有数的和

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

6、用户登陆（3次机会）

user_name = "root"
user_passwd = "root123"
count = 1
while count < 4:
    user = input("请输入用户名：")
    passwd = input("请输入密码：")
    if user == user_name and passwd == user_passwd : print("welcome",user) else: print("您输入的用户名或密码错误，请重新输入，错误数次：",count) count = count + 1 while count == 4: print("您输入的次数过多，请稍后再试！") break