day1，python基础习题

#使用while循环输入 1 2 3 4 5 6     8 9 10

count = 0
while count < 10:
    count = count + 1
    if count != 7:
     print(count)
    else:
     print('\n')
    continue

#求1-100的所有数的和：

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

输出 1-100 内的所有奇数

count = 1
while count < 100:
    if count % 2 != 0:
        print(count)
    count = count + 1

#方法2
count = 1
while count < 101
    print(count)
    count += 2

#输出 1-100 内的所有偶数

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

#求1-2+3-4+5 ... 99的所有数的和

power = 1
count = 0
sum = 0
while count < 99:
    count += 1
    power += 1
    sum = sum + count*((-1)**power)
print(sum)
#方法2
n = 1
sum = 0
sum1 = 0
while n < 100:
    if n % 2 ==0:
        sum = sum + n
    else:
        sum1 = sum1 + n
    n = n + 1
print(sum1 - sum)
#方法三
sum = 0
count = 1
while count < 100:
    if count % 2 == 0:
        sum = sum - count
    else:
        sum = sum + count
    count += 1
print(sum)

#用户登陆（三次机会重试）

user_name = 'admin'
pass_word = 123
count = 0
n = 3
while count < 3:
    name = input('请输入用户名')
    if name == user_name:
        pw = int(input('请输入密码'))
        if pw == pass_word:
            print('登陆成功')
            break
        elif count < 2:
            print("用户名密码错误，请重新输入")
            n = n - 1
            print('您还剩%d次机会'%n)
        else:
            print("您已经尝试3次，请明天再来，谢谢！")
        count = count + 1