Get mutually exclusive record groups by tag

I've got a flat CSV file with data like this:

tag1,pageA
tag2,pageA
tag3,pageA
tag1,pageB
tag4,pageB
tag5,pageC
tag5,pageD
tag4,pageE
tag6,pageE

I'd like to somehow segment the pages in to mutually exclusive groups depending on all tags they share.

For instance:

tag1,tag2,tag3,tag4,tag6 ==>
  pageA,pageB,pageE

tag5 ==>
  pageC,pageD

What would be a reasonable way to do this? I'm open to using Python, sqlite, or both.