为什么要继承自unittest.TestCase？

Question

What's the motivation behind having my unit test classes inherit from unittest.TestCase , rather than object ? Does it matter if I'm using Nose (or PyTest) instead of unittest ?

Answer 1

If you don't inherit from unit.TestCase , the testing framework won't know that you want those classes to be test cases. So when you try to run your tests, nothing will happen!

Answer 2

Inheriting from unittest.TestCase lets you use method like:

• setUp / tearDown to prepare the tests
• asssertEquals and many more assertions

When you use pytest , you can write tests directly as functions (no need to subclass anything). You can achieve the same set up / tear down pattern by using fixtures , and write assertions using the assert statement since pytest features a powerful assertion introspection .

nose also provide similar features (test functions with a with_setup decorator).