Python - Flatten a dict of lists into unique values?

Question

I have a dict of lists in python:

content = {88962: [80, 130], 87484: [64], 53662: [58,80]}

I want to turn it into a list of the unique val

Answer 1

Double set comprehension:

Python 3:

sorted({x for v in content.values() for x in v})

Python 2:

sorted({x for v in content.itervalues() for x in v})