Create empty ctable for given path.

        Parameters
        ----------
        path : string
            The path to rootdir of the new ctable.

def _init_ctable(self, path):
        """
        Create empty ctable for given path.

        Parameters
        ----------
        path : string
            The path to rootdir of the new ctable.
        """
        # Only create the containing subdir on creation.
        # This is not to be confused with the `.bcolz` directory, but is the
        # directory up one level from the `.bcolz` directories.
        sid_containing_dirname = os.path.dirname(path)
        if not os.path.exists(sid_containing_dirname):
            # Other sids may have already created the containing directory.
            os.makedirs(sid_containing_dirname)
        initial_array = np.empty(0, np.uint32)
        table = ctable(
            rootdir=path,
            columns=[
                initial_array,
                initial_array,
                initial_array,
                initial_array,
                initial_array,
            ],
            names=[
                'open',
                'high',
                'low',
                'close',
                'volume'
            ],
            expectedlen=self._expectedlen,
            mode='w',
        )
        table.flush()
        return table