def _is_numeric(self, values):
if len(values) > <NUM_LIT:0>:<EOL><INDENT>assert isinstance(values[<NUM_LIT:0>], (float, int)),"<STR_LIT>".format(<EOL>type(values[<NUM_LIT:0>]))<EOL><DEDENT>return True<EOL>
Check to be sure values are numbers before doing numerical operations.