python全栈开发之day01基础知识查漏补缺

python是一门什么语言

编程语言主要从以下几个角度进行分类，编译型和解释型、静态语言和动态语言、强类型定义语言和弱类型定义语言。



解释型语言更容易移植


综上所述：python是一门动态解释性的强类型定义语言

字符编码

python2默认用ASCII进行编码，python3默认用utf-8进行编码。

format格式化输出

name = input('name:')
age = input('age:')
job = input('job:')
salary = input('salary:')

#第一种format格式化输出方式
info = '''
---------- info of {_name}---------
Name:{_name}
age:{_age}
job:{_job}
salary:{_salary}
'''.format(_name=name,_age=age,_job=job,_salary=salary)


#第二种format格式化输出方式
info2 = '''
---------- info of {0}---------
Name:{0}
age:{1}
job:{2}
salary:{3}
'''.format(name,age,job,salary)

print(info2)

密文输入

python中以缩进来代表代码块，这样不仅可以节省代码量，而且结构清晰明了
while循环

age = 56
count = 0
while count<3:
    guess_age = int(input("guess age:"))
    if guess_age == age:
        print("答对了!")
        break
    elif guess_age > age:
        print("大了!")
    else:
        print("小了")
    count += 1

#while正常走完流程就执行
else:
    print("你已经试了太多次了")

编写登录接口

# 编写登录接口
# 1.输入用户名密码
# 2.认证成功后显示欢迎信息
# 3.输错三次后锁定
import ast

def login():
    count = 0
    with open("用户信息文件",'r',encoding='utf-8') as f:
        infos = f.readlines()
        # print(infos)
        while True:
            username = input("请输入用户名：")
            password = input("请输入密码：")
            for info in infos:
                if username in info:
                    info_dic = ast.literal_eval(info)  #字符串转字典
                    if count >= 1:
                        lock_info = info.replace("'status': '0'", "'status': '1'")
                        # print('lock_info',lock_info)
                        # print(infos)
                        with open("用户信息文件", 'w', encoding='utf-8') as fp:
                            for new_info in infos:
                                # print(new_info)
                                if username in new_info:
                                    fp.write(lock_info)
                                    continue
                                fp.write(new_info)
                        print("%s用户已被锁定" % info_dic['username'])
                        return

                    elif info_dic['status'] == '1':
                        print("%s用户已被锁定"%info_dic['username'])
                        return

                    elif username == info_dic['username'] and password == info_dic["password"]:
                        print("登录成功")
                        return
                    else:
                        print("用户名或密码错误，请重新登录！！！")
                        count += 1
                        # print(count)
                        break
            else:
                print("用户不存在")
                return

if __name__ == '__main__':
    login()