1 '''
 2 print("1.使用while循环输入 1 2 3 4 5 6     8 9 10")
 3 count = 1
 4 while count < 11:
 5     print(count)
 6     count = count + 1
 7     if count == 7:
 8         count = count + 1
 9 '''
10 
11 '''
12 print("2、求1-100的所有数的和")
13 sum = 0 
14 count = 1 
15 
16 while count<101:
17     sum = count + sum
18     count += 1
19     if count == 101:
20         print(sum)
21 '''
22 
23 '''
24 print("3、输出 1-100 内的所有奇数")
25 count = 0 
26 check = 2
27 while count < 101:
28     count += 1
29     if count % check == 1 and count != 101:
30         print(count)
31     else:
32         continue
33 '''
34 
35 '''
36 print("4、输出 1-100 内的所有偶数")
37 count = 0 
38 check = 2
39 while count < 101:
40     count += 1
41     if count % check == 0:
42         print(count)
43 '''
44 
45 
46 print("5、求1-2+3-4+5 ... 99的所有数的和")
47 sum = 0 
48 count1 = 1 
49 count2 = 1
50 while count1 < 100:
51     if count1 % 2 == 0:
52         count2 = -count1
53     elif count1 % 2 == 1:
54         count2 = count1 
55     sum = count2 + sum
56     count1 += 1
57 print(sum)
58 
59 #方法二
60 sum = 0
61 count = 1
62 while count < 100
63     if count % 2 =0:
64         sum -= count
65     else:
66         sum +=count
67     count += 1
68 print sum
69 
70
 1 print("6、用户登陆（三次机会重试）")
 2 count = 1
 3 while count < 5:
 4     Account_num = input('请输入账号')
 5     Password = input('请输入密码')
 6     if Account_num =='Elsa' and Password == '1234':
 7         print('登陆成功')
 8         break
 9     else:
10         print('登陆失败，您还有%d次登陆机会' %(4 - count))
11         if 4 - count == 0:
12             temp = input('是否还想再试试？')
13             if temp == 'YES':
14                 print('要不要脸啊你，盗号的吧')
15             else:
16                 print('就算你想试也没机会了，再见，哼')
17     count += 1