Magpies can be very scary to say the least. Not all Magpies swoop but unfortunately you have no way of knowing which do or don't.

We have lots of them living down our street but lucky for us they do not show the least interest in swooping any of us.

I read an article once about Magpies and apparently most do not swoop but if they have been harassed at any stage by humans they become swoopers.

No great advice to offer I am afraid but maybe this link below will help:
http://www.tams.act.gov.au/play/park...ingwithmagpies