Returns all symbols in the library

        Parameters
        ----------
        partial: None or str
            if not none, use this string to do a partial match on symbol names

        Returns
        -------
        list of str

def list_symbols(self, partial_match=None):
        """
        Returns all symbols in the library

        Parameters
        ----------
        partial: None or str
            if not none, use this string to do a partial match on symbol names

        Returns
        -------
        list of str
        """
        symbols = self._symbols.distinct(SYMBOL)
        if partial_match is None:
            return symbols
        return [x for x in symbols if partial_match in x]