day1

笔记计算机基础

编译型和解释型

优缺点

Python的分类

常量

变量

Python2 和Python3的区别

用户交互（input）

if语句（else elif）

while循环（flag continue break）

作业：

'''
start = 0
sum = 0
while start < 101:
    start = start + 1
    sum = sum + start
print(sum)
'''
'''
start = 0
while start < 100:
    start = start + 1
    result = start % 2 
    if result == 1:
        print(start)
    else :
        continue
'''
'''
start = 0
while start < 101:
    start = start + 1
    result = start % 2
    if result == 0:
        print(start)
    else:
        continue
'''
'''
start = 0
sum = 0
while start < 99:
    start = start + 1
    result = start % 2
    if result ==1:
        sum = sum + start
    else:
        sum = sum - start
print(sum)
'''
'''
count = 1
while count <= 3:
    name = input("请输入用户名")
    password = input("请输入密码")
    if name == 'xxx' and password == 'xxx':
        print("输入正确")
        break
    else:
        print("用户输入错误")
        count = count + 1
'''
start = 2
while start >= 0:
    name = input('请输入用户名：')
    password = input('请输入密码：')
    if name == 'xxx' and password == 'xxxxxx':
        print('登陆成功')
        break
    else:
        print('用户名或密码输入错误！')
        print('还有', start, '次机会')
        start = start - 1