this is patch

[ 988698 ] compiler.transformer fix for (a, b) = 1, 2

fixing bug

[ 988613 ] compiler.transformer and tuple unpacking

Lib/compiler/transformer.py

@@ -929,7 +929,7 @@ class Transformer:
         # loop to avoid trivial recursion
         while 1:
             t = node[0]
-            if t == symbol.exprlist or t == symbol.testlist:
+            if t == symbol.exprlist or t == symbol.testlist or t == symbol.testlist_gexp:
                 if len(node) > 2:
                     return self.com_assign_tuple(node, assigning)
                 node = node[1]

Lib/test/test_transformer.py

+import unittest
+from test import test_support
+from compiler import transformer, ast
+from compiler import compile
+
+class Tests(unittest.TestCase):
+  
+  def testMultipleLHS(self):
+    """ Test multiple targets on the left hand side. """
+    
+    snippets = ['a, b = 1, 2',
+                '(a, b) = 1, 2',
+                '((a, b), c) = (1, 2), 3']
+
+    for s in snippets:
+      a = transformer.parse(s)
+      assert isinstance(a, ast.Module)
+      child1 = a.getChildNodes()[0]
+      assert isinstance(child1, ast.Stmt)
+      child2 = child1.getChildNodes()[0]
+      assert isinstance(child2, ast.Assign)
+      
+      # This actually tests the compiler, but it's a way to assure the ast 
+      # is correct
+      c = compile(s, '<string>', 'single')
+      vals = {}
+      exec c in vals
+      assert vals['a'] == 1
+      assert vals['b'] == 2
+
+def test_main():
+    test_support.run_unittest(
+        Tests
+    )
+
+if __name__ == "__main__":
+    test_main()