Python学习第一课

#变量    age=18    #定义一个变量，会有三个特征：id(内存地址),type(类型),value(地址)    print(id(age),type(age),age)    单行注释（#）的快捷键 Windows下为 ctrl+?    Mac下为 command+?    多行注释为一对三个双引号（""" """）    #coding = utf-8 设置字符集    #变量的命名方式    # 1.驼峰体    # AgeOldBoy = 73  首字母大写    # 2.下划线    # age_of_oldboy = 84#常量      不可变化的量用户与程序交互在Python3中input()无论用户输入的是什么，都解释成为字符串name = input('请输入你的用户名： ')print(id(name),type(name),name) #name = 18在Python2中input()用户必须输入值，输入的是什么类型 就存成什么类型。raw_input()与Python3中的input()使用一样。浮点型floatheght = 1.81print(type(heght),heght)#整型 intage = 18print(type(age),age)#字符串 strname = '老男孩'print(type(name),name)#字符串拼接name = 'egon'msg = 'hello'print(name + msg)name = '字符串'print(name*10)列表：可以存储多个值。定义在中括号内可以用逗号分开的多个元素。元素可以是任意类型。hobbies = ['play','read','music','movie']print(hobbies[3])print(hobbies[-1])列表嵌套字典hobbies = {'name':'sipeng','age':18,'heght':1.89}print(hobbies['name'])print(hobbies['age'])print(hobbies['heght'])字典嵌套：字典嵌套字典，字典嵌套列表布尔类型# ture# falseage =19AGE =20print(age>AGE)print(age<AGE)格式化输出占位符 %s   %d%s 可以接收整型和字符串类型%d 只可以接收整型my name is xxx,my age is xxxname = input('user_name: ')age = input('user_age: ')print('my name is %s,my age is %s' %(name,age))print('my name is %s,my age is %d' %(name,int(age)))逻辑运算符and，or，notand  两边都成立才为Ture 否则为Falseor   两边又一边成立就为Ture 否则为Falsenot  取反流程控制语句 if...else...age = input('>>>: ')age = int(age)if age > 30:    print('叫阿姨~')else:    print('叫妹妹~')age = int(input('>>>: '))sex = input('>>>: ')is_pretty = bool(input('>>>: '))if sex == 'female' and age < 30 and is_pretty == True:    print('表白中~')else:    print('叫阿姨~')while循环while 条件:    循环体count = 0while count < 3:    print('lopo',count)    count += 1死循环while True:    print('死循环！')跳出while循环 brerkcount = 0while True:    if count > 100:        break    print(count)    count += 1continue 跳出本次循环count = 0while True:    if count <= 10:        if count == 7:            count += 1            continue        print(count)        count += 1

课后作业：

1.
# 基础需求：#     让用户输入用户名密码#     认证成功后显示欢迎信息#     输错三次后退出程序user_name = 'pengsilong'pass_word = '111111'count = 0while count<3:    username = input("please input your username: ")    password = input("please input your password: ")    if username == user_name and password == pass_word:        print("welcome to login! " + username)        break    else:        print("your username or password is error!")        count += 1
2.
# 基础需求：#     让用户输入用户名密码#     认证成功后显示欢迎信息#     输错三次后退出程序# 升级需求：#     可以支持多个用户登录 (提示，通过列表存多个账户信息)#     用户3次认证失败后，退出程序，再次启动程序尝试登录时，还是锁定状态（提示:需把用户锁定的状态存到文件里）name = ["张三","李四","王五"]pwd = ["111111","222222","333333"]count = 0while True:    username = input("请输入你的用户名： ")    if username not in name:        print("你输入的用户不存在~")        continue    else:        with open("lock_name.txt","r") as usr:            king = usr.read()            if username in king:                print(username + " 该用户已经被锁定~")                break    userpass = input("请输入你的密码： ")    if username == name[0] and userpass == pwd[0]:        print("登录成功~" + username)        break    elif username == name[1] and userpass == pwd[1]:        print("登录成功~" + username)        break    elif username == name[2] and userpass == pwd[2]:        print("登录成功~" + username)        break    else:        count += 1        print("用户名或密码错误~")        if count >= 3:            with open("lock_name.txt","a") as w:                w.write(username + ",")                print("输入密码错误次数过多 %s 已经被锁定"%username)                break