def __init__(self, index_file_path):
        """
        Open a line-number index for a text file.
        """
        self.index_path = Path(index_file_path)
        self.header_length = 34
        self.index_file = self._open_index()
def __init__ ( self , index_file_path ) : self . index_path = Path ( index_file_path ) self . header_length = 34 self . index_file = self . _open_index ( )
Open a line-number index for a text file.