Currently, I'm checking for the type with: if (function_result->ob_type == &PyInt_Type) I'd rather use the C-API equivalent of isinstance(function_result, IntType) but there doesn't seem to be one that's compatible with Python 2.1, too. Any suggestions? Gerhard -- This sig powered by Python! Außentemperatur in München: 16.4 °C Wind: 0.5 m/s