# coding:UTF-8
# @author:lsj
# @version:1.0

#1、通用文件copy工具实现
# src_file = input("请输入源文件路径：").strip()
# des_file = input("请输入目标文件路径：").strip()
# with open(r"{}".format(src_file),mode="rb") as f1,\
#         open(r"{}".format(des_file),mode='wb') as f2:
#     for line in f1:
#         f2.write(line)

#2、基于seek控制指针移动，测试r+、w+、a+模式下的读写内容
# 前提：创建一个a.txt文件，里面的内容是"abc你们好"
# 测试r+
# with open("a.txt",mode="r+",encoding="utf-8") as f:
#     print(f.tell())  # 0 指针在文件开头
#     print(f.read())  # abc你们好  文件全部内容
#     # res = f.seek(0,0)  # 0 指针在文件开头
#     res = f.seek(0,1)  # 0 指针在文件开头
#     print(res)
#     print(f.tell())  # 9

# 测试w+
# with open("a.txt",mode="w+",encoding="utf-8") as f:
    # print(f.read())  # io.UnsupportedOperation: not readable不支持读
    # f.write("abc你好")
    # f.seek(2,0)
    # print(f.tell()) # 2
    # print(f.seek(2,0))  # 2
    # f.seek(2,1)  #报错 io.UnsupportedOperation: can't do nonzero cur-relative seeks
    # print(f.tell())
    # f.seek(2,2)  # 报错：io.UnsupportedOperation: can't do nonzero end-relative seeks

# 测试a+
# with open("a.txt",mode="a+",encoding="utf-8") as f:
    # f.read()
    # print(f.read())  #
    # f.write("abc你好")
    # f.seek(2,0)  # # 2
    # print(f.tell())
    # f.seek(2,1)  #报错 io.UnsupportedOperation: can't do nonzero cur-relative seeks
    # print(f.tell())
    # f.seek(2,2)  # 报错
# # 3、tail -f access.log程序实现 # 永远获取日志的最后一行。
# with open('access.log',mode='rb') as f:
#     f.seek(0,2)
#     while True:
#         line=f.readlines()
#         if len(line) == 0:
#             pass
#         else:
#             print(line.decode('utf-8'),end='')


#4、周末作业参考在老师讲解完毕后（下午17：30开始讲解），练习熟练，明早日考就靠他俩
# 4.1：编写用户登录接口
# username = input("请输入您的账号：").strip()
# password = input("请输入密码：").strip()
# with open(r'user.txt',mode='rt',encoding="utf-8") as f:
#     for line in f:
#         user,pwd = line.strip().split(":")
#         if user == username and pwd == password:
#             print("登录成功！！")
#             break
#     else:
#         print("登录失败！！！")
# 4.2：编写程序实现用户注册后（注册到文件中），可以登录（登录信息来自于文件）
# username = input("请输入您的注册账号：").strip()
# password = input("请输入您的注册密码：").strip()
# with open("login.txt",mode="wt",encoding="utf-8") as w:
#     w.write("{}:{}\n".format({username},{password}))

dic = {
    "0":"退出",
    "1":"登录",
    "2":"注册"
}
while True:
    msg = """
    0 退出
    1 登录
    2 注册
    """
    print(msg)
    cmd = input('请输入命令编号>>: ').strip()
    if not cmd.isdigit():
        print('必须输入命令编号的数字，傻叉')
        continue
    # 判断当前用户如果不在dic字典中，执行
    if cmd not in dic:
        print('输入的命令不存在')
        continue
    if cmd == "0":
        print("退出")
        break
    if cmd == "1":
        username = input("请输入您的账号：").strip()
        password = input("请输入密码：").strip()
        with open('login.txt',mode='rt',encoding="utf-8") as f:
            for line in f:
                user,pwd = line.strip().split(":")
                if user == username and pwd == password:
                    print("登录成功！！")
                    break
            else:
                print("登录失败！！！")
    if cmd == "2":
        username = input("请输入您的注册账号：").strip()
        password = input("请输入您的注册密码：").strip()
        with open("login.txt",mode="at",encoding="utf-8") as w:
            w.write("{}:{}\n".format(username,password))
            print("注册成功可以登录！！！")
    print(dic.get(cmd))