Day 1 入门知识及作业

python特征

python2 与 python3 区别

2的源码不标准, 重复代码多

3同意, 标准, 去重

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编译型: 一次性执行所有程序编译成二进制文件, 开发效率低, 运行速度快, 不能跨平台.

解释型: 一行一行执行, 开发效率高, 可以快平台, 运行速度较慢.

 

 

 

 

a = '''

多行注释

可以赋值

给变量

　　'''

 

while　　else

当while被 break 打断, 不执行else

 

 

 

练习题 Day 1

1、使用while循环输入 1 2 3 4 5 6     8 9 10

num = 0
while num <= 9:
    num += 1
    if num > 6 and num < 8:
        continue
    print(num)

 

2、求1-100的所有数的和

num = 1
sum = 0

while num < 101:
    sum += num
    num += 1

print(sum)

3、输出 1-100 内的所有奇数

odd = 0

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

a = 0

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

while a < 101:
    print(a)
    a += 2

 4、输出 1-100 内的所有偶数

odd = tuple(range(1,100))

for i in odd:
    if i % 2 == 1:
        print(i)

5、求1-2+3-4+5 ... 1000的所有数的和

odd = tuple(range(1,1000))
sum = 0

for i in odd:
    if i % 2 != 0:
        sum -= i
    else:
        sum += i


print(sum)

6、用户登陆（三次机会重试）

error = 0
left = 3 - error

NAME = 'XIONG'
PASSWORD = 'qq112233'

while left > 0:
    name = input("Please input your sign in name: ")
    password = input("Please input your password: ")
    if name == NAME and password == PASSWORD:
        print("YOUR NAME IS: " + name)
        print("YOUR PASSWORD IS: " + password)
        print('Congratulations,you are correct')
        break
    else:
        error += 1
        if error == 3:
            print('Sorry, too many times error')
            break
        print("YOUR NAME IS: " + name)
        print("YOUR PASSWORD IS: " + password)
        print('Sorry, you are wrong. Please try again')
        print(str(left - error) + 'time(s) left')