parameters: (cls, filename, start_byte, chunk_size, callback=None,
                        enable_callback=True)
return_statement: return cls(f, start_byte, chunk_size, file_size, callback,
                     enable_callback)
docstring: Convenience factory function to create from a filename.
  
          :type start_byte: int
          :param start_byte: The first byte from which to start reading.
  
          :type chunk_size: int
          :param chunk_size: The max chunk size to read.  Trying to read
              pass the end of the chunk size will behave like you've
              reached the end of the file.
  
          :type full_file_size: int
          :param full_file_size: The entire content length associated
              with ``fileobj``.
  
          :type callback: function(amount_read)
          :param callback: Called whenever data is read from this object.
  
          :type enable_callback: bool
          :param enable_callback: Indicate whether to invoke callback
              during read() calls.
  
          :rtype: ``ReadFileChunk``
          :return: A new instance of ``ReadFileChunk``
docstring_summary: Convenience factory function to create from a filename.
docstring_tokens: Convenience factory function to create from a filename .
function: def from_filename(cls, filename, start_byte, chunk_size, callback=None,
                        enable_callback=True):
          """Convenience factory function to create from a filename.
  
          :type start_byte: int
          :param start_byte: The first byte from which to start reading.
  
          :type chunk_size: int
          :param chunk_size: The max chunk size to read.  Trying to read
              pass the end of the chunk size will behave like you've
              reached the end of the file.
  
          :type full_file_size: int
          :param full_file_size: The entire content length associated
              with ``fileobj``.
  
          :type callback: function(amount_read)
          :param callback: Called whenever data is read from this object.
  
          :type enable_callback: bool
          :param enable_callback: Indicate whether to invoke callback
              during read() calls.
  
          :rtype: ``ReadFileChunk``
          :return: A new instance of ``ReadFileChunk``
  
          """
          f = open(filename, 'rb')
          file_size = os.fstat(f.fileno()).st_size
          return cls(f, start_byte, chunk_size, file_size, callback,
                     enable_callback)
function_tokens: def from_filename ( cls , filename , start_byte , chunk_size , callback = None , enable_callback = True ) : f = open ( filename , 'rb' ) file_size = os . fstat ( f . fileno ( ) ) . st_size return cls ( f , start_byte , chunk_size , file_size , callback , enable_callback )