Testing the code we write is important, so we should use available tools to write tests that are readable, thorough, and DRY (Don't Repeat Yourself). Subtests, added in Python3.4, make accomplishing each of these three goals easier. This talk goes through some examples of how subtests make testing 1) more readable, 2) more thorough, and 3) more DRY. The result: better apps and fewer bugs.