Python and Object.assign

from functools import reduce


def assign(target, *sources):
    def _update(target, source):
        target.update(source)
        return target

    return reduce(
        _update, filter(lambda x: isinstance(x, dict), sources), target)

>>> obj = {'a': 1}
>>> copy = assign({}, obj)
>>> copy
{'a': 1}

>>> obj1 = {'a': 0, 'b': {'c': 0}}
>>> obj2 = assign({}, obj1)
>>>
>>> obj1['a'] = 1
>>> obj1
{'a': 1, 'b': {'c': 0}}
>>>
>>> obj2['a'] = 2
>>> obj2
{'a': 2, 'b': {'c': 0}}
>>>
>>> obj2['b']['c'] = 3
>>> obj1
{'a': 1, 'b': {'c': 3}}
>>> obj2
{'a': 2, 'b': {'c': 3}}

>>> assign({'a': 1}, {'a': 2}, {'a': 3})
{'a': 3}

>>> assign({'a': 1}, None, {'b': 2}, 4)
{'a': 1, 'b': 2}