Pytest单元测试框架实战之Pytest用例运行规则

1.Pytest测试用例运行规则

---

 在pytest单元测试框架下面执行用例，需要满足以下几个特点：

　　1. 文件名以test_*.py开头或者*_test.py

　　2. 测试类、测试函数以test开头

　　3. 所有的包必须要有 __init__.py文件

一般在cmd命令行下面执行pytest用例有3种方法。大家可以选择使用，我推荐第一种：

　　pytest  文件名

　　py.test  文件名

　　python -m pytest 文件名

如果运行某个测试类下面的具体函数，可以使用：pytest  文件名：：测试函数名

如果在测试过程中，遇到测试停止的方法可以加 -x参数： pytests -x 文件名

E:untitled1>pytest -x collect.py
============================= test session starts =============================
platform win32 -- Python 3.5.1, pytest-5.0.1, py-1.8.0, pluggy-0.12.0
rootdir: E:untitled1
collected 2 items

collect.py .F                                                            [100%]

================================== FAILURES ===================================
_____________________________ TestClass.test_two ______________________________

self = <collect.TestClass object at 0x00000000036A4A58>

    def test_two(self):
        x = 'hello'
>       assert hasattr(x, 'check')
E       AssertionError: assert False
E        +  where False = hasattr('hello', 'check')

collect.py:102: AssertionError
===================== 1 failed, 1 passed in 0.08 seconds ======================

从结果可以看出第二个测试用例没有运行成功并且停止了。当错误数达到某个量级时，测试停止，参数为：maxfail=num 示例如下：

E:untitled1>pytest --maxfail=1 collect.py
============================= test session starts =============================
platform win32 -- Python 3.5.1, pytest-5.0.1, py-1.8.0, pluggy-0.12.0
rootdir: E:untitled1
collected 3 items

collect.py .F

================================== FAILURES ===================================
_____________________________ TestClass.test_two ______________________________

self = <collect.TestClass object at 0x000000000368FCF8>

    def test_two(self):
        x = 'hello'
>       assert hasattr(x, 'check')
E       AssertionError: assert False
E        +  where False = hasattr('hello', 'check')

collect.py:102: AssertionError
===================== 1 failed, 1 passed in 0.08 seconds ======================

2.在Pycharm中编写测试代码

---

 在编写测试代码运行之前需要把切换pytest运行环境。file-->setting-->tools-->python intergrated tools--->default test runner 切换为 py.test  然后编写如下测试代码：

import pytest

class TestClass:

    def test_one(self):
        x = 'hello'
        assert 'h' in x

    def test_two(self):
        x = 'hello'
        assert hasattr(x, 'check')

    def test_secound(self):
        assert 'x' in 'ddd'

if __name__ == '__main__':
    pytest.main('-q test_class.py')

运行结果如下：   （其中:     .表示测试结果是通过的 pass  E:表示errror  脚本中可能存在问题  F表示failed 测试结果不通过）

C:Python35python.exe "C:Program Files (x86)JetBrainsPyCharm 5.0.3helperspycharmpytestrunner.py" -p pytest_teamcity E:/untitled1/test_class.py "-k TestClass and test_secound"
Testing started at 17:28 ...
============================= test session starts =============================
platform win32 -- Python 3.5.1, pytest-5.0.1, py-1.8.0, pluggy-0.12.0
rootdir: C:Program Files (x86)JetBrainsPyCharm 5.0.3jrejrein
collected 3 items / 2 deselected / 1 selected

. F
self = <test_class.TestClass object at 0x000000000365EB38>

    def test_secound(self):
>       assert 'x' in 'ddd'
E       AssertionError: assert 'x' in 'ddd'

E:untitled1	est_class.py:106: AssertionError


================================== FAILURES ===================================
___________________________ TestClass.test_secound ____________________________

self = <test_class.TestClass object at 0x000000000365EB38>

    def test_secound(self):
>       assert 'x' in 'ddd'
E       AssertionError: assert 'x' in 'ddd'

E:untitled1	est_class.py:106: AssertionError
=================== 1 failed, 2 deselected in 0.06 seconds ====================