python - Nested arguments not compiling -

i'm trying compile code found here: http://semprog.com/psw/chapter2/simpletriple.py

...into python3 module. runs fine when choose 'run module' in idle, receive following syntax error when try create distribution:

file "/usr/local/lib/python3.2/dist-packages/simpletriple.py", line 9     def add(self, (sub, pred, obj)):                   ^ syntaxerror: invalid syntax 

can point out wrong syntax?

here complete code:

import csv  class simplegraph: def __init__(self):     self._spo = {}     self._pos = {}     self._osp = {}  def add(self, (sub, pred, obj)):     """     adds triple graph.     """     self._addtoindex(self._spo, sub, pred, obj)     self._addtoindex(self._pos, pred, obj, sub)     self._addtoindex(self._osp, obj, sub, pred)  def _addtoindex(self, index, a, b, c):     """     adds triple specified index.     """     if not in index: index[a] = {b:set([c])}     else:         if b not in index[a]: index[a][b] = set([c])         else: index[a][b].add(c)  def remove(self, (sub, pred, obj)):     """     remove triple pattern graph.     """     triples = list(self.triples((sub, pred, obj)))     (delsub, delpred, delobj) in triples:         self._removefromindex(self._spo, delsub, delpred, delobj)         self._removefromindex(self._pos, delpred, delobj, delsub)         self._removefromindex(self._osp, delobj, delsub, delpred)  def _removefromindex(self, index, a, b, c):     """     removes triple index , clears empty indermediate structures.     """     try:         bs = index[a]         cset = bs[b]         cset.remove(c)         if len(cset) == 0: del bs[b]         if len(bs) == 0: del index[a]     # keyerrors occur if term missing, means wasn't valid delete:     except keyerror:         pass  def triples(self, (sub, pred, obj)):     """     generator on triple store.     returns triples match given triple pattern.      """     # check terms present in order use correct index:     try:         if sub != none:              if pred != none:                 # sub pred obj                 if obj != none:                     if obj in self._spo[sub][pred]: yield (sub, pred, obj)                 # sub pred none                 else:                     retobj in self._spo[sub][pred]: yield (sub, pred, retobj)             else:                 # sub none obj                 if obj != none:                     retpred in self._osp[obj][sub]: yield (sub, retpred, obj)                 # sub none none                 else:                     retpred, objset in self._spo[sub].items():                         retobj in objset:                             yield (sub, retpred, retobj)         else:             if pred != none:                 # none pred obj                 if obj != none:                     retsub in self._pos[pred][obj]:                         yield (retsub, pred, obj)                 # none pred none                 else:                     retobj, subset in self._pos[pred].items():                         retsub in subset:                             yield (retsub, pred, retobj)             else:                 # none none obj                 if obj != none:                     retsub, predset in self._osp[obj].items():                         retpred in predset:                             yield (retsub, retpred, obj)                 # none none none                 else:                     retsub, predset in self._spo.items():                         retpred, objset in predset.items():                             retobj in objset:                                 yield (retsub, retpred, retobj)     # keyerrors occur if query term wasn't in index, yield nothing:     except keyerror:         pass  def value(self, sub=none, pred=none, obj=none):     retsub, retpred, retobj in self.triples((sub, pred, obj)):         if sub none: return retsub         if pred none: return retpred         if obj none: return retobj         break     return none  def load(self, filename):     f = open(filename, "rb")     reader = csv.reader(f)     sub, pred, obj in reader:         sub = unicode(sub, "utf-8")         pred = unicode(pred, "utf-8")         obj = unicode(obj, "utf-8")         self.add((sub, pred, obj))     f.close()  def save(self, filename):     f = open(filename, "wb")     writer = csv.writer(f)     sub, pred, obj in self.triples((none, none, none)):         writer.writerow([sub.encode("utf-8"), pred.encode("utf-8"), obj.encode("utf-8")])     f.close()  if __name__ == "__main__": g = simplegraph() g.add(("blade_runner", "name", "blade runner")) g.add(("blade_runner", "name", "blade runner")) g.add(("blade_runner", "release_date", "june 25, 1982")) g.add(("blade_runner", "directed_by", "ridley scott"))  print list(g.triples((none, none, none))) print list(g.triples(("blade_runner", none, none))) print list(g.triples(("blade_runner", "name", none))) print list(g.triples(("blade_runner", "name", "blade runner"))) print list(g.triples(("blade_runner", none, "blade runner"))) print list(g.triples((none, "name", "blade runner"))) print list(g.triples((none, none, "blade runner")))  print list(g.triples(("foo", "name", "blade runner"))) print list(g.triples(("blade_runner", "foo", "blade runner"))) print list(g.triples(("blade_runner", "name", "foo"))) 

pep 3113 explains why feature, "tuple parameter unpacking", removed in python 3. explains how port code uses them. in case you'd need change function like:

def add(self, (sub, pred, obj)):     self._addtoindex(self._spo, sub, pred, obj)     self._addtoindex(self._pos, pred, obj, sub)     self._addtoindex(self._osp, obj, sub, pred) 

to version passes tuple single parameter , unpacks manually:

def add(self, sub_pred_obj):     sub, pred, obj = sub_pred_obj     self._addtoindex(self._spo, sub, pred, obj)     self._addtoindex(self._pos, pred, obj, sub)     self._addtoindex(self._osp, obj, sub, pred)