Support for augmented assignment to subscript inside try..except block

CHANGELOG.md

@@ -1,5 +1,9 @@
 # **Upcoming release**
 
+## Bug fixes
+
+- #459 Fix bug while extracting method with augmented assignment to subscript in try block (@dryobates)
+
 # Release 0.23.0
 
 ## Syntax support

rope/refactor/extract.py

@@ -843,8 +843,12 @@ def _Assign(self, node):
 
     def _AugAssign(self, node):
         ast.walk(node.value, self)
-        self._read_variable(node.target.id, node.target.lineno)
-        self._written_variable(node.target.id, node.target.lineno)
+        if isinstance(node.target, ast.Subscript):
+            target_id = node.target.value.id
+        else:
+            target_id = node.target.id
+        self._read_variable(target_id, node.target.lineno)
+        self._written_variable(target_id, node.target.lineno)
 
     def _ClassDef(self, node):
         self._written_variable(node.name, node.lineno)

ropetest/refactor/extracttest.py

@@ -1762,6 +1762,30 @@ def g():
         """)
         self.assertEqual(expected, refactored)
 
+    def test_extract_method_and_augmentedj_assignment_in_try_block(self):
+        code = dedent("""\
+            def f():
+                any_subscriptable = [0]
+                try:
+                    any_subscriptable[0] += 1
+                except Exception:
+                    pass
+        """)
+        start, end = self._convert_line_range_to_offset(code, 2, 6)
+        refactored = self.do_extract_method(code, start, end, "g")
+        expected = dedent("""\
+            def f():
+                g()
+
+            def g():
+                any_subscriptable = [0]
+                try:
+                    any_subscriptable[0] += 1
+                except Exception:
+                    pass
+        """)
+        self.assertEqual(expected, refactored)
+
     def test_extract_and_not_passing_global_functions(self):
         code = dedent("""\
             def next(p):