day13 作业

目录

• 1、编写文件修改功能，调用函数时，传入三个参数（修改的文件路径，要修改的内容，修改后的内容）既可完成文件的修改
• 2、编写tail工具
• 3、编写登录功能
• 4、编写注册功能
• 选做题：编写ATM程序实现以下功能，数据源于文件db.txt

1、编写文件修改功能，调用函数时，传入三个参数（修改的文件路径，要修改的内容，修改后的内容）既可完成文件的修改

import os
def file_update(file_path,old_msg,new_msg):
    with open("b.txt","r",encoding="utf-8") as f 
            ,open(f"{file_path}\b.txt","w",encoding="utf-8") as f1:
        for line in f:
            f1.write(line.replace(f"{old_msg}",f"{new_msg}"))
    os.remove("b.txt")
file_update("locked","a","b")

2、编写tail工具

import time
def tail():
    with open("log.txt","rb") as f:
        f.seek(0,2)
        while True:
            new_msg = f.readline()
            if len(new_msg)==0:
                time.sleep(1)
            else:
                print(new_msg.decode("utf-8"))
tail()
#另一个文件
def write_log():
    with open("log.txt","a",encoding="utf-8") as f:
        msg = input("请输入日志内容")
        f.write(f"
{msg}")
write_log()

3、编写登录功能

def login():
    user_inp = input("your name >")
    pwd_inp = input("your msg >")
    with open("a.txt","r",encoding="utf-8") as f:
        for line in f :
            username,password = line.strip().split(":")
            if username==user_inp and pwd_inp == password:
                print("登录成功")
                break
        else:
            print("输入错误")
login()

4、编写注册功能

def register():
    username = input("请输入注册的用户名：")
    password = input("请输入注册的密码：")
    with open("a.txt","a",encoding="utf-8") as f :
        f.write(f"
{username}:{password}")
register()

选做题：编写ATM程序实现以下功能，数据源于文件db.txt

1、充值功能：用户输入充值钱数，db.txt中该账号钱数完成修改

2、转账功能：用户A向用户B转账1000元，db.txt中完成用户A账号减钱，用户B账号加钱

3、提现功能：用户输入提现金额，db.txt中该账号钱数减少

4、查询余额功能：输入账号查询余额

5、用户登录成功后，内存中记录下该状态，上述功能以当前登录状态为准，必须先登录才能操作

import os
def recharge():
    ''' 充值功能'''
    name_inp = input("请输入要充值的账号>")
    money_inp = input("请输入要充值的金钱>")
    with open("db.txt","r",encoding="utf-8") as f ,
        open(".db.txt.swap","w",encoding="utf-8") as f1:
            for line in f :
                if name_inp in line :
                    name,money = line.strip().split(":")
                    new_money = int(money_inp)+int(money)
                    f1.write(line.replace(money,str(new_money)))
                else:
                    f1.write(line)
    os.remove("db.txt")
    os.rename(".db.txt.swap","db.txt")

def transfer():
    '''转账功能'''
    transfer_name_inp = input("请输入转账人姓名：")
    collector_name_inp = input("请输入收账人姓名：")
    money_inp = input("请输入转账金额")
    with open("db.txt","r",encoding="utf-8") as f ,
        open(".db.txt.swap","w",encoding="utf-8") as f1:
        for line in f :
            if transfer_name_inp in line :
                transfer_name,transfer_money=line.strip().split(":")
                new_money = int(transfer_money)-int(money_inp)
                f1.write(line.replace(transfer_money,str(new_money)))
            elif collector_name_inp in line:
                collector_name,collector_money=line.strip().split(":")
                new_money = int(collector_money)+int(money_inp)
                f1.write(line.replace(collector_money,str(new_money)))
            else:
                f1.write(line)
    os.remove("db.txt")
    os.rename(".db.txt.swap","db.txt")
def cash_withdrawal():
    '''提现功能'''
    name_inp = input("请输入提现账号的姓名：")
    money_inp = input("请输入提现的金额：")
    with open("db.txt","r",encoding="utf-8") as f ,
        open(".db.txt.swap","w",encoding="utf-8") as f1:
        for line in f:
            if name_inp in line:
                name,money = line.strip().split(":")
                new_money = int(money)-int(money_inp)
                f1.write(line.replace(money,str(new_money)))
            else:
                f1.write(line)
    os.remove("db.txt")
    os.rename(".db.txt.swap","db.txt")

def login():
    '''登录功能'''
    user_inp = input("your name >")
    pwd_inp = input("your msg >")
    with open("a.txt","r",encoding="utf-8") as f:
        for line in f :
            username,password = line.strip().split(":")
            if username==user_inp and pwd_inp == password:
                print("登录成功")
                return 1
        else:
            print("输入错误")

def query():
    '''查询功能'''
    name_inp=input("请输入你要查询的用户名：")
    with open("db.txt","r",encoding="utf-8")as f :
        for line in f :
            name,money = line.strip().split(":")
            if name_inp in line:
                print(money)
                break

#主程序
list1=["1","2","3","4"]
while True:
    res = login()
    if res:
        while True:
            print('''
                   欢迎来到只能充值转账提现的劣质ATM系统
                               1.充值
                               2.转账
                               3.提现
                               4.查询
                   ''')
            cmd = input("请输入指令>")
            if cmd ==list1[0]:
                recharge()
            elif cmd == list1[1]:
                transfer()
            elif cmd == list1[2]:
                cash_withdrawal()
            elif cmd == list1[3]:
                query()
            else:
                print("非法输入")