I observed: >>> 1e308 1e+308 >>> 1e309 1.#INF >>> 1e308*10 1.#INF >>> type(1e308*10) <type 'float'> >>> -1e309 -1.#INF >>> Is there a token or a name to input this strange float object, __repr__esented by 1.0#INF directly? For instance as follows: def fun(a, mini=-?1.?INF? , maxi = ?1.?INF?): ....etc... Regards Gregor L.