Issue 166 in SPARQLWrapper solved

CONTRIBUTORS

@@ -45,6 +45,7 @@ Niklas Lindström
 Pierre-Antoine Champin
 Phil Dawes
 Phillip Pearson
+Pritish Wadhwa
 Ron Alford
 Remi Chateauneu
 Sidnei da Silva

rdflib/plugins/sparql/algebra.py

@@ -416,24 +416,31 @@ def _aggs(e, A):
         aggvar = Variable("__agg_%d__" % len(A))
         e["res"] = aggvar
         return aggvar
-
-
+
 def _findVars(x, res):
     """
     Find all variables in a tree
     """
+    seenVars = set()
     if isinstance(x, Variable):
-        res.add(x)
+        if x not in seenVars:
+            res.append(x)
+            seenVars.add(x)        
     if isinstance(x, CompValue):
         if x.name == "Bind":
-            res.add(x.var)
+            if x.var not in seenVars:
+                res.append(x.var)
+                seenVars.add(x.var)
             return x  # stop recursion and finding vars in the expr
         elif x.name == "SubSelect":
             if x.projection:
-                res.update(v.var or v.evar for v in x.projection)
+                tempList = [v.var or v.evar for v in x.projection]
+                for a in tempList:
+                    if a not in seenVars:
+                        res.append(a)
+                        seenVars.add(a)
             return x
 
-
 def _addVars(x, children):
     """
     find which variables may be bound by this part of the query
@@ -548,7 +555,7 @@ def translate(q):
     q.where = traverse(q.where, visitPost=translatePath)
 
     # TODO: Var scope test
-    VS = set()
+    VS = list()
     traverse(q.where, functools.partial(_findVars, res=VS))
 
     # all query types have a where part

test/test_issues/test_issue166.py

@@ -0,0 +1,10 @@
+import pytest
+from rdflib import Graph
+import rdflib
+
+
+def test_issue_166() -> None:
+    g = Graph()
+    query="SELECT * { ?a ?b ?c } LIMIT 10"
+    qres=g.query(query)
+    assert(qres.vars == [rdflib.term.Variable('a'), rdflib.term.Variable('b'), rdflib.term.Variable('c')])