@unittest 快速理解setUp，tearDown ,setUpclass ,tearDownclass区别是什么

 # coding=utf-8

import unittest


class ClassTest(unittest.TestCase):
    @classmethod
    def setUpClass(cls):
        print("starting before all method,i just do one times")
        
    @classmethod
    def tearDownClass(cls):
        print("ending after all method ended,i just do one times")
        
    def setUp(self):
        print("prepare  before every method,must execute me one times")
    
    def tearDown(self):
        print("ending after each method finish ,must execute me one time")
        
    # tip:python 测试用例必须以test开头
    def test_method1(self):
        print("i am method 1")
        
    def test_method2(self):
        print("i am method2")
if __name__ == "__main__":
    unittest.main()  #程序入口
    
结果如下：
C:\Python27\python.exe "D:\Pycharm\PyCharm 5.0.4\helpers\pycharm\utrunner.py" C:\Users\Administrator\PycharmProjects\py3project\ttt.py true
Testing started at 22:30 ...
starting before all method,i just do one times
prepare  before every method,must execute me one times
i am method 1
ending after each method finish ,must execute me one time
prepare  before every method,must execute me one times
i am method2
ending after each method finish ,must execute me one time
ending after all method ended,i just do one times