get.py

"""
Clojure-inspired ``get_in`` function which gets value from nested dicts,
returning ``None`` if a key is not found.
"""
import operator

def get_in(obj, *keys):
    try:
        return reduce(operator.getitem, keys, obj)
    except (KeyError, IndexError):
        return None


def main():
    obj = {
        'one': 1,
        'two': {
            'one': 11
        },
        'three': [1, 2, 3]
    }

    assert 1 == get_in(obj, 'one')
    assert 11 == get_in(obj, 'two', 'one')
    assert 1 == get_in(obj, 'three', 0)
    assert None == get_in(obj, 'four')
    assert None == get_in(obj, 'two', 'three')
    assert None == get_in(obj, 'three', 5)


if __name__ == '__main__':
    main()