`approvaltests` is the Python port of ApprovalTests, an open source
assertion/verification library to aid testing.

You can use ApprovalTests to verify objects that require more than a
simple assert including long strings, large arrays, and complex hash
structures and objects. ApprovalTests really shines when you need a more
granular look at the test failure. Sometimes, trying to find a small
difference in a long string printed to STDOUT is just too hard!
ApprovalTests solves this problem by providing reporters which let you
view the test results in one of many popular diff utilities.