On May 23, 2011, at 12:49 PM, Mateusz Paprocki wrote: > Hi, > > On 23 May 2011 20:46, Aaron S. Meurer <asmeu...@gmail.com> wrote: > > On May 23, 2011, at 12:40 PM, Chris Smith wrote: > > > Aaron S. Meurer wrote: > >>> On May 22, 2011, at 9:31 PM, Renato Coutinho wrote: > >>> > >>>> On Mon, May 23, 2011 at 12:28 AM, Mateusz Paprocki > >>>> <matt...@gmail.com> wrote: > >>>>> Hi, > >>>>> > >>>>> On 23 May 2011 05:18, smichr <smi...@gmail.com> wrote: > >>>>>> > >>>>>> Will list(e.free_symbols) be OS independent? > >>>>> > >>>>> .free_symbols is implemented using sets so it is platform (hash) > >>>>> dependent (I mean order of elements). > >>>> > >>>> But sets don't have any ordering (except for printing or iterating, > >>>> but you shouldn't use it). I think sorted(list(e.free_symbols)) > >>>> should > >>>> be safe. > >>>> > >>>> Cheers, > >>>> Renato > >>> > >>> No, sorted uses __le__, which for symbols uses the hash, so that too > >>> will be platform dependent (granted it's better than list(set), > >>> which might return a different thing within the same session). > >>> > >>> Why do you need to have a list instead of a set? > >>> > > If you have `solve([x+y-3,x-y-1])` you need an unambiguous way to return > > the tuples if you aren't going to return the results with the symbols. You > > could get set([Tuple(1, 2)]) or set([Tuple(2, 1)]) so you need a way to > > internally send back something unambiguous. > > > > I think it should just return the result with the symbols. > > Or use sorted_key to get hash independent ordering.
Even then, it isn't clear at all to the user what refers to what. I think we should return a dictionary. Aaron Meurer > > > Aaron Meurer > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sympy@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. > > > Mateusz > > -- > You received this message because you are subscribed to the Google Groups > "sympy" group. > To post to this group, send email to sympy@googlegroups.com. > To unsubscribe from this group, send email to > sympy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sympy?hl=en. -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.
