python-open函数

open函数,该函数用于文件处理

操作文件时,一般需要经历如下步骤:

  • 打开文件
  • 操作文件

一、打开文件

1

文件句柄 = open('文件路径', '模式')

打开文件时,需要指定文件路径和以何等方式打开文件,打开后,即可获取该文件句柄,日后通过此文件句柄对该文件操作。

打开文件的模式有:

  • r,只读模式(默认)。
  • w,只写模式。【不可读;不存在则创建;存在则删除内容;】
  • a,追加模式。【可读;   不存在则创建;存在则只追加内容;】

"+" 表示可以同时读写某个文件

  • r+,可读写文件。【可读;可写;可追加】
  • w+,写读
  • a+,同a

"U"表示在读取时,可以将 \r \n \r\n自动转换成 \n (与 r 或 r+ 模式同使用)

  • rU
  • r+U

"b"表示处理二进制文件(如:FTP发送上传ISO镜像文件,linux可忽略,windows处理二进制文件时需标注)

  • rb
  • wb
  • ab


  • class TextIOWrapper(_TextIOBase):

        """

        Character and line based layer over a BufferedIOBase object, buffer.

       

        encoding gives the name of the encoding that the stream will be

        decoded or encoded with. It defaults to locale.getpreferredencoding(False).

       

        errors determines the strictness of encoding and decoding (see

        help(codecs.Codec) or the documentation for codecs.register) and

        defaults to "strict".

       

        newline controls how line endings are handled. It can be None, '',

        '\n', '\r', and '\r\n'.  It works as follows:

       

        * On input, if newline is None, universal newlines mode is

          enabled. Lines in the input can end in '\n', '\r', or '\r\n', and

          these are translated into '\n' before being returned to the

          caller. If it is '', universal newline mode is enabled, but line

          endings are returned to the caller untranslated. If it has any of

          the other legal values, input lines are only terminated by the given

          string, and the line ending is returned to the caller untranslated.

       

        * On output, if newline is None, any '\n' characters written are

          translated to the system default line separator, os.linesep. If

          newline is '' or '\n', no translation takes place. If newline is any

          of the other legal values, any '\n' characters written are translated

          to the given string.

       

        If line_buffering is True, a call to flush is implied when a call to

        write contains a newline character.

        """

        def close(self, *args, **kwargs): # real signature unknown

            关闭文件

            pass

     

        def fileno(self, *args, **kwargs): # real signature unknown

            文件描述符 

            pass

     

        def flush(self, *args, **kwargs): # real signature unknown

            刷新文件内部缓冲区

            pass

     

        def isatty(self, *args, **kwargs): # real signature unknown

            判断文件是否是同意tty设备

            pass

     

        def read(self, *args, **kwargs): # real signature unknown

            读取指定字节数据

            pass

     

        def readable(self, *args, **kwargs): # real signature unknown

            是否可读

            pass

     

        def readline(self, *args, **kwargs): # real signature unknown

            仅读取一行数据

            pass

     

        def seek(self, *args, **kwargs): # real signature unknown

            指定文件中指针位置

            pass

     

        def seekable(self, *args, **kwargs): # real signature unknown

            指针是否可操作

            pass

     

        def tell(self, *args, **kwargs): # real signature unknown

            获取指针位置

            pass

     

        def truncate(self, *args, **kwargs): # real signature unknown

            截断数据,仅保留指定之前数据

            pass

     

        def writable(self, *args, **kwargs): # real signature unknown

            是否可写

            pass

     

        def write(self, *args, **kwargs): # real signature unknown

            写内容

            pass

     

        def __getstate__(self, *args, **kwargs): # real signature unknown

            pass

     

        def __init__(self, *args, **kwargs): # real signature unknown

            pass

     

        @staticmethod # known case of __new__

        def __new__(*args, **kwargs): # real signature unknown

            """ Create and return a new object.  See help(type) for accurate signature. """

            pass

     

        def __next__(self, *args, **kwargs): # real signature unknown

            """ Implement next(self). """

            pass

     

        def __repr__(self, *args, **kwargs): # real signature unknown

            """ Return repr(self). """

            pass

     

        buffer = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default

     

        closed = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default

     

        encoding = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default

     

        errors = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default

     

        line_buffering = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default

     

        name = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default

     

        newlines = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default

     

        _CHUNK_SIZE = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default

     

        _finalizing = property(lambda self: object(), lambda self, v: None, lambda self: None)  # default

posted @ 2018-02-28 11:02  努力乄小白  阅读(188)  评论(0编辑  收藏  举报