Hi, On Fri, Sep 16, 2011 at 11:48 AM, Peter Cock <p.j.a.cock at googlemail.com> wrote: > Thanks, I'll use that. Its a shame that wasn't in Python 2.5 though, > my copy of Jython doesn't support it either. The older and more robust way to check this is: "__pypy__" in sys.builtin_module_names Armin