老男孩python学习_day001作业

1.使用while循环输入 1 2 3 4 5 6     8 9 10

# 有空格
i = 0
while i < 10:
    i += 1
    if i == 7:
        print(' ')
    else:
        print(i)

# 没空格
i = 0
while i < 10:
    i += 1
    if i == 7:
        continue
    print(i)

# 没空格
i = 0
while i < 10:
    i += 1
    if i == 7:
        pass
    else:
        print(i)

2.求1-100的所有数的和

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

3.输出 1-100 内的所有奇数

# 法一
i = 0
while i < 100:
    i += 1
    if i%2 == 1:
        print(i)

# 法二
i = 0
while i < 100:
    i += 1
    if i%2 == 0:
        continue
    print(i)

# 法三
i = 1
while i < 100:
    print(i)
    i += 2

4.输出 1-100 内的所有偶数

# 法一
i = 0
while i < 100:
    i += 1
    if i%2 == 0:
        print(i)

# 法二
i = 0
while i < 100:
    i += 1
    if i%2 == 1:
        continue
    print(i)

# 法三
i = 2
while i < 101:
    print(i)
    i += 2

5.求1-2+3-4+5 ... 99的所有数的和

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

6.用户登录，三次机会重试

#自己写的...
count = 3
username = 'yyh'
password = '123'
while count > 0:
    name = input('请输入用户名：')
    if name == username:
        while count > 0:
            word = input('请输入密码：')
            if word == password:
                count = -1
                print('登录成功！')
            else:
                count -= 1
                tip = '密码错误，你还有%d次机会'%(count)
                print(tip)
    else:
        count -= 1
        tip = '用户名错误，你还有%d次机会' %(count)
        print(tip)
if count == 0:
    print('登录失败，三次机会已用完')

i = 0
while i <3:
    username = input('请输入账号：')
    password = input('请输入密码：')
    if username == 'yyh' and password == '123':
        print('登陆成功')
    else:
        print('登录失败，请重新登录')
    i += 1
print('三次机会已用完')