文件流操作

文件IO主要学习就是open，close

   第一个参数 要读写文件路径    第二个参数 以何种方式进行读写

 w = write写            r = read读            t = text文本

b = binary字节数据(二进制)    a = append追加

import os

一、 

1,"w(t)"表示写一个文本文件,并且会将原文件的内容清空

      write_file = open("1.txt", "wt")

      write_file.write("123123123")

      write_file.close()

 2,“r(t)”表示读取文本文件

      read_file = open("1.txt", "r")

      s = read_file.read()

      print(s)

     当读/写二进制数据的时候使用 r/wb

file:/C:/Users/Shinelon/Desktop/python%20课程/1.txtread_file = open("头像1.png", "rb")

      s = read_file.read()

      print(s)

 3,encoding参数表示文件的编码类型，只有当以文本形式读写文件时encoding才起作用

      read_file = open("1.txt","rt",encoding="utf-8")

      s = read_file.read()

      print(s)

 4,a模式会在原文件的内容之后继续添加新内容

     append_file = open("tttt.txt", "at")

     append_file.write("\n哈哈\n")

     append_file.write("呵呵\n")

     append_file.close()

 5,边读边写

     append_file = open("tttt.txt", "rt+")

     s = append_file.read()

     append_file.write("\n哈哈\n")

     append_file.write("呵呵\n")

     append_file.close()

 6,复制文件

     read_file = open("头像1.png","rb")

     b = read_file.read()

     write_file = open("头像1的副本.png","wb")

     write_file.write(b)

     read_file.close()

     write_file.close()

 7,循环读写

  read_file = open("13-sys_os模块.mp4","rb")

 write_file = open("1.mp4","wb")

 while True:

     data = read_file.read(1024 * 1024)

     if not data:

         break

     write_file.write(data)

 read_file.close()

 write_file.close()

 8,创建一个copy(src,dst)

   src就是源文件的绝对路径     dst就是副本保存的绝对路径

 def copy(src,dst):

     read_file = open(src,"rb")   创建读取文件的IO

     write_file = open(dst,"wb")  创建写入文件的IO

     while True:

         data = read_file.read(1024 * 1024)

         if not data:

             break

         write_file.write(data)

     read_file.close()

     write_file.close()

 copy('/Users/musicbear/项目：飞机大战.md','1.md')

 9,创建一个文件叫做1.txt 写入0-100以内的所有自然数，每写一个数字换一行

      f = open("1.txt","wt")

      for i in range(0,101):

           f.write(f"{i}\n")

      f.close()

 10,with 关键字在其代码片段执行完毕后会自动释放文件/网络的占用

     with open("1.txt","wt") as f:

           for i in range(0,101):

                f.write(f"{i}\n")

 11,读取刚刚写好的文件（1.txt），读取70字节的内容并将其打印到屏幕上

      with open("1.txt","rt") as f:

            content = f.read(70)

            print(content)

 12,读取1.txt的所有内容，然后读取到的内容写到2.txt当中

 with open("1.txt","rt") as rf:

            s = rf.read()

       with open("2.txt","wt") as wf:

            wf.write(s)

 13,读取1.txt中的内容，一次读取10个字节，每读一次，将读到内容写到2.txt中，直到读完整个文件

      with open("1.txt","rt") as rf:

         with open("2.txt","wt") as wf:

         while True:

             text = rf.read(10)

             if not text:

                 break

             wf.write(text)

def copy(src, dst):

    with open(src, "rb") as rf:

        with open(dst, "wb") as wf:

            while True:

                data = rf.read(1024 * 1024)

                if not data:

                    break

                wf.write(data)

14,复制指定的目录(imagetest)

①创建指定目录的副本(imagetest_副本)②将目录中的文件都复制一份

③将目录中的子目录进行递归

def copy_dir(src, dst):

     os.mkdir(dst)     创建副本文件夹

     files = os.listdir(src)  读取src下的所有文件

 for f in files:

        abs_f = src + os.sep + f

        if os.path.isfile(abs_f):   如果是文件，直接复制

            copy(abs_f, dst + os.sep + f)

        elif os.path.isdir(abs_f):

            copy_dir(abs_f, dst + os.sep + f)

copy_dir("/Users/musicbear/imgtest", "/Users/musicbear/imgtest_副本")