patch.dict

Patch a dictionary, or dictionary like object, and restore the dictionary
to its original state after the test, where the restored dictionary is
a copy of the dictionary as it was before the test.

`in_dict` can be a dictionary or a mapping like container. If it is a
mapping then it must at least support getting, setting and deleting items
plus iterating over keys.

`in_dict` can also be a string specifying the name of the dictionary, which
will then be fetched by importing it.

`values` can be a dictionary of values to set in the dictionary. `values`
can also be an iterable of `(key, value)` pairs.

If `clear` is True then the dictionary will be cleared before the new
values are set.

`patch.dict` can also be called with arbitrary keyword arguments to set
values in the dictionary::

    with patch.dict('sys.modules', mymodule=Mock(), other_module=Mock()):
        ...

`patch.dict` can be used as a context manager, decorator or class
decorator. When used as a class decorator `patch.dict` honours
`patch.TEST_PREFIX` for choosing which methods to wrap.