Print the existing tables in a database

        :example: ``ds.tables()``

def tables(self):
        """Print the existing tables in a database

        :example: ``ds.tables()``
        """
        if self._check_db() == False:
            return
        try:
            pmodels = self._tables()
            if pmodels is None:
                return
            num = len(pmodels)
            s = "s"
            if num == 1:
                s = ""
            msg = "Found " + colors.bold(str(num)) + " table" + s + ":\n"
            msg += "\n".join(pmodels)
            self.info(msg)
        except Exception as e:
            self.err(e, "Can not print tables")