python开发基础----练习1

1、使用while循环输出1 2 3 4 5 6 8 9 10

#!/usr/bin/env python

count = 1
while count <= 10:
    if count != 7:
        print(count)
    count += 1

2、求1-100的所有数的和

#!/usr/bin/env python

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

3、输出1-100内所有的奇数

#!/usr/bin/env python

num = 1

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

4、输出1-100内所有的偶数

#!/usr/bin/env python

num = 1

while num <= 100:
    if not (num % 2) :
        print(num)
    num += 1

5、求1-2+3-4+5...99的所有数的和

#!/usr/bin/env python

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

6、用户登录（三次机会重试）

#!/usr/bin/env python

username = 'xieys'
password = '123456'
fail = 1

while fail <= 3:
users = raw_input("input username:")
passwd = raw_input("input password:")
if ( users == username ) and ( passwd == password ):
print("login success!")
break
else:
print("username or password wrong!")
fail += 1