Python基础题 1

1、使用while循环输入 1 2 3 4 5 6     8 9 10

count = 0
while count <= 9:
    count += 1
    if count == 7:continue
    print(count)

 或：

# 把7换成空格
count = 0
while count < 10:
    count += 1
    if count == 7:
        print(' ')
    else:
        print(count)
# 不输入空格
count = 0
while count < 10:
    count += 1
    if count == 7:continue
    print(count)
# 用pass
count = 0
while count <= 9:
    count += 1
    if count == 7:
        pass              #直接跳过
    else:
        print(count)

2、求1-100的所有数的和

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

3、输出 1-100 内的所有奇数

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

 或：

# 第一种方法
count = 1
while count < 101:
    print(count)
    count += 2
# 第二种方法
count = 1
while count < 101:
    if count % 2 == 1:
        print(count)
    count += 1

4、输出 1-100 内的所有偶数

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

5、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)

 或：

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

6、用户登陆（三次机会重试）

user_name = 'admin'
password = 'admin'
count = 0
while count < 3:
    count += 1
    name = input ('请输入用户名：')
    if name == user_name:
        pw = input('请输入密码：')
        if pw == password:
            print('登陆成功')
            break
        else :print('密码错误!')
        if count == 3:print('登陆超过三次！请明天重试。')
    else :
        print('用户名不存在!')
        if count == 3 :print('登陆超过三次！请明天重试。')

 或：

i = 0
while i <3:
    username = input('请输入账号：')
    password = input('请输入密码：')
    if username == 'admin' and password == 'admin':
        print('登陆成功')
    else:
        print('登录失败，请重新登录')
    i += 1