Small fix in Python grammars (misread tuples, issue #68)

examples/python2.g

@@ -100,13 +100,14 @@ comp_op: "<"|">"|"=="|">="|"<="|"<>"|"!="|"in"|"not" "in"|"is"|"is" "not"
          | molecule "[" [subscriptlist] "]" -> getitem
          | molecule "." NAME -> getattr
          | atom
-?atom: "(" [yield_expr|testlist_comp] ")"
+?atom: "(" [yield_expr|testlist_comp] ")" -> tuple
     |   "[" [listmaker] "]"
     |   "{" [dictorsetmaker] "}"
     |   "`" testlist1 "`"
+    |   "(" test ")"
     |   NAME | number | string+
 listmaker: test ( list_for | ("," test)* [","] )
-?testlist_comp: test ( comp_for | ("," test)* [","] )
+?testlist_comp: test ( comp_for | ("," test)+ [","] | ",")
 lambdef: "lambda" [paramlist] ":" test
 ?subscriptlist: subscript ("," subscript)* [","]
 subscript: "." "." "." | test | [test] ":" [test] [sliceop]

examples/python3.g

@@ -121,12 +121,13 @@ AWAIT: "await"
      | "{" [dictorsetmaker] "}" -> dict
      | NAME -> var
      | number | string+
+     | "(" test ")"
      | "..." -> ellipsis
      | "None"    -> const_none
      | "True"    -> const_true
      | "False"   -> const_false
 
-testlist_comp: (test|star_expr) ( comp_for | ("," (test|star_expr))* [","] )
+?testlist_comp: (test|star_expr) ( comp_for | ("," (test|star_expr))+ [","] | ",")
 subscriptlist: subscript ("," subscript)* [","]
 subscript: test | [test] ":" [test] [sliceop]
 sliceop: ":" [test]