def addCleanup(self, function, *args, **kwargs):        """Add a function, with arguments, to be called when the test is
        completed. Functions added are called on a LIFO basis and are
        called after tearDown on test failure or success.

        Cleanup items are called even if setUp fails (unlike tearDown)."""
        self._cleanups.append((function, args, kwargs))

添加針對每個(gè)測試用例執(zhí)行完tearDown()方法之后的清理方法，添加進(jìn)去的函數(shù)按照LIFO的順序，通過參數(shù)添加進(jìn)去
如果setUp()執(zhí)行失敗，就不會執(zhí)行tearDown()，自然也不會執(zhí)行addCleanup()里添加的函數(shù)。
使用場景：正常的測試用例，創(chuàng)建資源后，需要清理環(huán)境再在用例中刪除資源，或者tearDown()后進(jìn)行資源清理，不方便，如果用了addCleanup()后，直接在用例中寫入函數(shù)，在tearDown()用例后，會再次調(diào)用addCleanup來刪除資源，減少代碼量以及遺漏刪除。

# _*_ encoding:utf-8 _*_

from selenium import webdriver
from selenium.webdriver.common.by import By
import unittest
import time

class Baidu(unittest.TestCase):

    def abc(self,a,b):
       print(a+b)

    def setUp(self):
        self.driver = webdriver.Ie()
        self.driver.implicitly_wait(10)
        self.base_url = 'http://www.baidu.com'
        print ("This is setUp")

    def test_baidu_search(self):
        driver = self.driver
        driver.get(self.base_url)
        driver.find_element_by_id("kw").send_keys("HTMLTestRunner")
        driver.find_element_by_id("su").click()
        cleanups = ('abcdefg','123312')
        self.addCleanup(self.abc,
                        cleanups[0], cleanups[1])

    def tearDown(self):
        self.driver.quit()
        print ("This is tearDown")

if __name__ == '__main__':
    unittest.main()
執(zhí)行結(jié)果如下，可以看到會在用例結(jié)束之后，執(zhí)行addCleanup里的函數(shù)，因此可以用來進(jìn)行，測試環(huán)境數(shù)據(jù)清理工作。
Ran 1 test in 12.008s
OK
This is tearDown
abcdefg123312
Process finished with exit code 0