Python os 模块，O_TEXT 实例源码

def flags(self):
        '''
        Adapted from http://hg.python.org/cpython/file/84cf25da86e8/Lib/_pyio.py#l154

        See also open(2) which explains the modes

        os.O_BINARY and os.O_TEXT are only available on Windows.
        '''
        return (
            ((self.reading and not self.updating) and os.O_RDONLY or 0) |
            ((self.writing and not self.updating) and os.O_WRONLY or 0) |
            ((self.creating_exclusively and not self.updating) and os.O_EXCL or 0) |
            (self.updating and os.O_RDWR or 0) |
            (self.appending and os.O_APPEND or 0) |
            ((self.writing or self.creating_exclusively) and os.O_CREAT or 0) |
            (self.writing and os.O_TRUNC or 0) |
            ((self.binary and hasattr(os, 'O_BINARY')) and os.O_BINARY or 0) |
            ((self.text and hasattr(os, 'O_TEXT')) and os.O_TEXT or 0)
        )

def create_file_from_handle(handle, mode="r"):
    """Return a Python :class:`file` around a ``Windows`` HANDLE"""
    fd = msvcrt.open_osfhandle(handle, os.O_TEXT)
    return os.fdopen(fd, mode, 0)

def File2FileObject(pipe, mode):
  """Make a C stdio file object out of a win32 file handle"""
  if mode.find('r') >= 0:
    wmode = os.O_RDONLY
  elif mode.find('w') >= 0:
    wmode = os.O_WRONLY
  if mode.find('b') >= 0:
    wmode = wmode | os.O_BINARY
  if mode.find('t') >= 0:
    wmode = wmode | os.O_TEXT
  return os.fdopen(msvcrt.open_osfhandle(pipe.Detach(),wmode),mode)