day12作业

#1、通用文件copy工具实现

src_file=input("请输入原文件路径>>")
des_file=input("请输入原文件路径>>")

with open(src_file,"rb") as f,
    open(des_file,"ab") as f_new:
    for i in f:
        f_new.write(i)

#2、基于seek控制指针移动，测试r+、w+、a+模式下的读写内容

#r+
with open("access.log","r+",encoding="utf-8") as f:
    print(f.tell())   #文件开始指针位置
    f.write("hahaha")
    print(f.tell())   #写入操作后文件位置
    f.seek(0,0)
    print(f.tell())    #指针移动到文件开头

#w+
with open("access.log","w+",encoding="utf-8") as f:
    print(f.tell())   #文件开始指针位置
    f.write("hahaha")
    print(f.tell())   #写入操作后文件位置
    f.seek(0,0)
    print(f.tell())    #指针移动到文件开头

#a+
with open("access.log","a+",encoding="utf-8") as f:
    print(f.tell())   #文件开始指针位置
    f.write("hahaha")
    print(f.tell())   #写入操作后文件位置
    f.seek(0,0)
    print(f.tell())    #指针移动到文件开头

#3、tail -f access.log程序实现

import os

file_inp=input("请输入文件路径>>")
if os.path.exists(file_inp):
    with open(file_inp,"rb") as f:
        f.seek(0,2)
        while True:
            line = f.readline()
            if line:
                print(line.decode("utf-8"),end="")
else:
    print("{}文件不存在.".format(file_inp))