Fix sys.path completions, #1298

jedi/evaluate/sys_path.py

@@ -99,7 +99,7 @@ def check_sys_path_modifications(module_context):
     def get_sys_path_powers(names):
         for name in names:
             power = name.parent.parent
-            if power.type in ('power', 'atom_expr'):
+            if power is not None and power.type in ('power', 'atom_expr'):
                 c = power.children
                 if c[0].type == 'name' and c[0].value == 'sys' \
                         and c[1].type == 'trailer':

test/test_api/test_interpreter.py

@@ -356,3 +356,9 @@ def test_name_not_findable():
     setattr(X, 'NOT_FINDABLE', X.hidden)
 
     assert jedi.Interpreter("X.NOT_FINDA", [locals()]).completions()
+
+
+def test_sys_path_docstring():  # Was an issue in #1298
+    import jedi
+    s = jedi.Interpreter("from sys import path\npath", line=2, column=4, namespaces=[locals()])
+    s.completions()[0].docstring()