Make sure that function executions are errors as well, see #90

parso/python/errors.py

@@ -1095,5 +1095,9 @@ class _NamedExprRule(_CheckAssignmentRule):
                         # (a.b := c)
                         message = 'cannot use named assignment with attribute'
                         self.add_issue(namedexpr_test, message=message)
+                    elif first_child.value == '(':
+                        # (a[i] := x)
+                        message = 'cannot use named assignment with function call'
+                        self.add_issue(namedexpr_test, message=message)
         else:
             self._check_assignment(first, is_namedexpr=True)

test/failing_examples.py

@@ -327,6 +327,7 @@ if sys.version_info[:2] >= (3, 8):
         '(lambda: x := 1)',
         # Case 3
         '(a[i] := x)',
+        '(a(i) := x)',
         # Case 4
         '(a.b := c)',
         # Case 5