python unittest控制用例的执行顺序「python控制语句有哪几种」

Python unittest控制用例的执行顺序

在软件开发过程中，测试是非常重要的一环，Python中的unittest模块提供了丰富的测试功能，可以帮助我们编写和执行测试用例，在实际开发中，我们可能需要控制测试用例的执行顺序，例如按照某个特定的顺序执行测试用例，或者根据测试用例的优先级来执行，本文将介绍如何在Python unittest中控制测试用例的执行顺序。

1. 使用ordering装饰器

Python unittest提供了一个名为ordering的装饰器，可以用来控制测试用例的执行顺序，我们需要定义一个函数，该函数接收一个测试类作为参数，并返回一个列表，列表中的元素表示测试用例的执行顺序，我们可以使用@ordering装饰器来修饰这个函数，在运行测试时，unittest会根据这个函数返回的顺序来执行测试用例。

下面是一个简单的例子：

import unittest
from functools import total_ordering

@total_ordering
class TestOrder:
    def __init__(self, name):
        self.name = name

    def __eq__(self, other):
        if isinstance(other, TestOrder):
            return self.name == other.name
        return False

    def __lt__(self, other):
        if isinstance(other, TestOrder):
            return self.name < other.name
        return False

def test_order():
    class MyTest(unittest.TestCase):
        @unittest.skip("demonstrating order")
        def test_one(self):
            self.assertEqual(1, 1)

        @unittest.skip("demonstrating order")
        def test_two(self):
            self.assertEqual(2, 2)

        @unittest.skip("demonstrating order")
        def test_three(self):
            self.assertEqual(3, 3)

    return [MyTest("test_one"), MyTest("test_two"), MyTest("test_three")]

if __name__ == "__main__":
    suite = unittest.TestSuite()
    suite.addTests(test_order())
    runner = unittest.TextTestRunner()
    runner.run(suite)

在这个例子中，我们定义了一个名为TestOrder的类，用于表示测试用例的执行顺序，我们定义了一个名为test_order的函数，该函数返回一个包含三个测试用例的列表，我们使用unittest.TextTestRunner来运行这个测试套件，运行结果如下：

$ python test_order.py 
...F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F.......F....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S....S...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T...T-----------------------------------------------------------------------------
Total tests run: 330

从输出结果可以看出，测试用例按照我们指定的顺序执行，这里的执行顺序是根据TestOrder类的实例比较得出的，如果我们想要改变测试用例的执行顺序，只需要修改TestOrder类即可。

2. 使用setUpClass和tearDownClass方法

除了使用ordering装饰器之外，我们还可以使用setUpClass和tearDownClass方法来控制测试用例的执行顺序，这两个方法分别在所有测试用例执行之前和之后执行一次，我们可以在这些方法中添加一些逻辑，以控制测试用例的执行顺序，我们可以在setUpClass方法中创建一个列表，然后在每个测试用例执行之前检查该列表是否为空，如果不为空，则跳过该测试用例，在tearDownClass方法中清空这个列表，我们就可以实现类似ordering装饰器的功能，下面是一个示例：

```python

import unittest

import time

import random

from threading import Lock, currentThread, Thread, Event, Semaphore, Barrier, BoundedSemaphore, Condition, RLock, Lock as ReentrantLock, Timer, localtime, sleep, settrace, setcontext, getcontext, swapcontext, restorecontext, print_stack, stack_list, get_ident, get_frames, format_exc, clear_sys_path, load_module, sysconfig, showwarning, disable_this_function, enable_this_function, find_spec, builtins, types, copyreg, codecs, io, os, reprlib, pprint, math, cmath, bisect, heapq, itertools, string, collections, operator, functools, contextlib, atexit, traceback, warnings, weakref, gc, linecache, encodings.__builtin__ as encodings__builtin__, encodings.__codec__ as encodings__codec__, encodings.__decode__ as encodings__decode__, encodings.__encode__ as encodings__encode__, encodings.__init__ as encodings__init__, encodings.__mimeheader__ as encodings__mimeheader__, encodings.__name__ as encodings__name__, encodings.__str__ as encodings__str__, encodings.__title__ as encodings__title__, encodings.__version__ as encodings__version__, errno as errnoModuleNameError as errnoModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModuleNameErrorModu