dictproxy was used in Python 2 and it was renamed to mappingproxy
in Python 3.3.
Patch by Julien.
Objects such as modules and instances have an updateable :attr:`~object.__dict__`
attribute; however, other objects may have write restrictions on their
:attr:`~object.__dict__` attributes (for example, classes use a
- dictproxy to prevent direct dictionary updates).
+ :class:`types.MappingProxyType` to prevent direct dictionary updates).
Without an argument, :func:`vars` acts like :func:`locals`. Note, the
locals dictionary is only useful for reads since updates to the locals