Support unpacking for dicts in assignments

Close #268

3 files changed, 43 insertions, 13 deletions

diff --git a/ChangeLog b/ChangeLog
index 722d4284..ac4a38b5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,10 @@ What's New in astroid 2.0?
 
 Release Date: Unknown
 
+   * Support unpacking for dicts in assignments
+
+     Close #268
+
    * Add support for inferring functools.partial
 
      Close #125
diff --git a/astroid/protocols.py b/astroid/protocols.py
index 2d72ec82..08d3b7a4 100644
--- a/astroid/protocols.py
+++ b/astroid/protocols.py
@@ -373,7 +373,15 @@ def _resolve_asspart(parts, asspath, context):
     asspath = asspath[:]
     index = asspath.pop(0)
     for part in parts:
-        if hasattr(part, 'getitem'):
+        assigned = None
+        if isinstance(part, nodes.Dict):
+            # A dictionary in an iterating context
+            try:
+                assigned, _ = part.items[index]
+            except KeyError:
+                return
+
+        elif hasattr(part, 'getitem'):
             index_node = nodes.Const(index)
             try:
                 assigned = part.getitem(index_node, context)
@@ -381,19 +389,23 @@ def _resolve_asspart(parts, asspath, context):
             # unexpected exception ?
             except (exceptions.AstroidTypeError, exceptions.AstroidIndexError):
                 return
-            if not asspath:
-                # we achieved to resolved the assignment path, don't infer the
-                # last part
-                yield assigned
-            elif assigned is util.Uninferable:
+
+        if not assigned:
+            return
+
+        if not asspath:
+            # we achieved to resolved the assignment path, don't infer the
+            # last part
+            yield assigned
+        elif assigned is util.Uninferable:
+            return
+        else:
+            # we are not yet on the last part of the path search on each
+            # possibly inferred value
+            try:
+                yield from _resolve_asspart(assigned.infer(context), asspath, context)
+            except exceptions.InferenceError:
                 return
-            else:
-                # we are not yet on the last part of the path search on each
-                # possibly inferred value
-                try:
-                    yield from _resolve_asspart(assigned.infer(context), asspath, context)
-                except exceptions.InferenceError:
-                    return
 
 
 @decorators.raise_if_nothing_inferred
diff --git a/astroid/tests/unittest_inference.py b/astroid/tests/unittest_inference.py
index 0d41c2e7..099966bc 100644
--- a/astroid/tests/unittest_inference.py
+++ b/astroid/tests/unittest_inference.py
@@ -4461,5 +4461,19 @@ def test_cannot_infer_call_result_for_builtin_methods():
         next(lenmeth.infer_call_result(None, None))
 
 
+def test_unpack_dicts_in_assignment():
+    ast_nodes = extract_node('''
+    a, b = {1:2, 2:3}
+    a #@
+    b #@
+    ''')
+    first_inferred = next(ast_nodes[0].infer())
+    second_inferred = next(ast_nodes[1].infer())
+    assert isinstance(first_inferred, nodes.Const)
+    assert first_inferred.value == 1
+    assert isinstance(second_inferred, nodes.Const)
+    assert second_inferred.value == 2
+
+
 if __name__ == '__main__':
     unittest.main()