inspired by Clojure's get-in function

getin.py

def getin(d, keys, default=None):
    '''
    >>> d = {'foo': {'bar': {'baz': 1}}}
    >>> getin(d, ['foo', 'bar', 'baz'])
    1
    >>> getin(d, ['foo', 'bar'])
    {'baz': 1}
    >>> getin(d, ['foo', 'oops'], default=0)
    0
    '''
    if not keys:
        return d
    key = keys[0]
    if len(keys) == 1:
        return d.get(key, default)
    res = d.get(key)
    if isinstance(res, dict):
        return getin(res, keys[1:], default=default)
    return default