get.py

def get(obj, attr, default=None):
    """
    Fetch an attribute deeply nested on an object or dict, return `default` if not found
    
    >>> class Foo: pass

    >>> f = Foo()
    >>> f.a = Foo()
    >>> f.a.b = Foo()
    >>> f.a.b.c = True

    >>> get(f, "a.b.c")
    True

    >>> get(f, "a.b.d") is None
    True

    >>> d = {'a': {'b': {'c': True}}}
    >>> get(d, 'a.b.c')
    True

    >>> get(d, 'a.b.d') is None
    True
    """
    attrs = attr.split('.')
    temp = obj
    for attr in attrs:
        try:
            if isinstance(temp, dict):
                temp = temp[attr]
            else:
                temp = getattr(temp, attr)
        except (KeyError, AttributeError):
            return default
    return temp