Improve code snippet

python · ambv · Nov 18, 2021 · Nov 3, 2021 · Nov 3, 2021 · Nov 3, 2021
commit c1955d7faf533388d45718dab6e0b8d3d3922784
@@ -2282,17 +2282,21 @@ follows something like the following process to decide whether
 :meth:`~object.__getitem__` or :meth:`~object.__class_getitem__` should be
 called::
 
+   from inspect import isclass
+
    def subscribe(obj, x):
+       """Return the result of the expression `obj[x]`"""
+
        class_of_obj = type(obj)
 
        # If the class of `obj` defines `__getitem__()`,
        # call `type(obj).__getitem__()`
        if hasattr(class_of_obj, '__getitem__'):
            return class_of_obj.__getitem__(obj, x)
 
-       # Else, if `obj` defines `__class_getitem__()`,
+       # Else, if `obj` is a class and defines `__class_getitem__()`,
        # call `obj.__class_getitem__()`
-       elif hasattr(obj, '__class_getitem__'):
+       elif isclass(obj) and hasattr(obj, '__class_getitem__'):
            return obj.__class_getitem__(x)
 
        # Else, raise an exception