Most pythonic way of rotating a circular list to a canonical point

[Paul Rubin]

Lukas Barth <mail at tinloaf.de> writes:
>> [Concatenated Hashes]
> Also, that still doesn't compute that one "canonical ordering"...

It was intended to get rid of the need.  What is the actual application?

How does this sound?  To circularly hash [a,b,c,d] use:

  H([b-a, c-b, d-c, a-d])

where H is your favorite hash function on a list of that element type.
That should give the same hash value for any rotation of the list.
It generalizes in the obvious way to other lengths.