(obj, attr)
Follow an attribute chain.

    If you have a chain of objects where a.foo -> b, b.foo-> c, etc,
    use this to iterate over all objects in the chain. Iteration is
    terminated by getattr(x, attr) is None.

    Args:
        obj: the starting object
        attr: the name of the chaining attribute

    Yields:
        Each successive object in the chain.
Follow an attribute chain.
Follow an attribute chain .
def attr_chain(obj, attr):
    """Follow an attribute chain.

    If you have a chain of objects where a.foo -> b, b.foo-> c, etc,
    use this to iterate over all objects in the chain. Iteration is
    terminated by getattr(x, attr) is None.

    Args:
        obj: the starting object
        attr: the name of the chaining attribute

    Yields:
        Each successive object in the chain.
    """
    next = getattr(obj, attr)
    while next:
        yield next
        next = getattr(next, attr)
def attr_chain ( obj , attr ) : next = getattr ( obj , attr ) while next : yield next next = getattr ( next , attr )