day011作业

作业：

# 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

ANSR：

# 方式一：
def file_change():

    src_file_abs_path = input("Please input src_file_abs_path: ").strip()
    src_data = input("Please input src_data: ").strip()
    dst_data = input("Please input dst_data: ").strip()
    with open(r"{}".format(src_file_abs_path),mode="rt",encoding="utf-8") as read_f:
        data = read_f.read()
    with open(r"{}".format(src_file_abs_path),mode="wt",encoding="utf-8") as write_f:
        write_f.write(data.replace(src_data,dst_data))

        
# 方式二：
def file_change():
    import os
    src_file_abs_path = input("Please input src_file_abs_path: ").strip()
    src_data = input("Please input src_data: ").strip()
    dst_data = input("Please input dst_data: ").strip()
    with open(r"{}".format(src_file_abs_path), mode="rt", encoding="utf-8") as read_f, 
            open(r"{}.swap".format(src_file_abs_path), mode="wt", encoding="utf-8") as write_f:
        for line in read_f:
            data = line.replace(src_data, dst_data)
            write_f.write(data)

    os.remove(r"{}".format(src_file_abs_path))
    os.rename(r"{}.swap".format(src_file_abs_path), r"{}".format(src_file_abs_path))

# 2、编写tail工具

ANSR：

def tail(src_file_abs_path):
    import time
    with open(r"{}".format(src_file_abs_path), mode="rb") as f:
        f.seek(0,2)
        while True:
            line = f.readline()
            if len(line) == 0:
                time.sleep(0.1)
            else:
                print(line.decode("utf-8"),end="")

# 3、编写登录功能

ANSR：

def login():
    inp_name = input("Please input your user name:  ").strip()
    inp_pwd = input("Please input your user password:  ").strip()
    with open("taskdb.txt",mode="rt",encoding="utf-8") as read_f:
        for line in read_f:
            name, pwd, *_=line.strip("
").split(":")
            if name == inp_name and inp_pwd == pwd:
                print("login successful")
                break
        else:
            print("Username or password error")

# 4、编写注册功能

ANSR：

def register():
    inp_name = input("Please input your user name:  ").strip()
    inp_pwd = input("Please input your user password:  ").strip()
    with open("taskdb.txt",mode="rt",encoding="utf-8") as read_f:
        for line in read_f:
            name, pwd, *_=line.strip("
").split(":")
            if name == inp_name:
                print("Username exists")
                break
        else:
            with open("taskdb.txt", mode="at", encoding="utf-8") as write_f:
                write_f.write("{}:{}:0
".format(inp_name,inp_pwd))
            print("register successful")

# 5、编写用户认证功能

ANSR：

user_list=[]
def auth():
    inp_name = input("Please input your user name:  ").strip()
    if inp_name not in user_list:
        inp_pwd = input("Please input your user password:  ").strip()
        with open("taskdb.txt", mode="rt", encoding="utf-8") as read_f:
            for line in read_f:
                name, pwd, *_ = line.strip("
").split(":")
                if name == inp_name and inp_pwd == pwd:
                    print("login successful")
                    break
            else:
                print("Username or password error")
    else:
        pass

# 选做题：编写ATM程序实现下述功能，数据来源于文件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

ANSR：

/

# 选做题中的选做题：登录功能
# 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

ANSR：

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