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