前言

pytest測驗框架也是主流的一個測驗框架，推薦使用該框架，對比unnitest框架來說，其效率更高，前面的文章講解了，如何使用pytest，這篇文章一起來看下如何針對pytest的測驗用例進行控制，

本篇文章是《Selenium3自動化測驗【38】單元測驗Pytest》的后續，建議連續閱讀，效果更佳，

1. 測驗用例的運行控制

Pytest執行用例的方式，不單單是Pytest這一種方式，Pytest提供了3種運行方式執行測驗用例，

pytest（一般采用該種方式）；
pytest test.py或pytest test.py；
python –m pytest，

在pytestDemo目錄下，新創建一個Demo_test.py檔案，代碼如下：

# 乘法，回傳a*b的值
def multi(a,b):
    return a*b

# 除法，回傳a/b的值
def divide(a,b):
    return a/b

class TestClass:
    def test_multi(self):
        assert multi(3, 3) == 6

    def test_divide(self):
        assert divide(3, 2) == 4

1.1 方式1：pytest

格式為：【pytest 檔案名/】或進入pytestDemo目錄下，運行pytest，執行某個目錄下所有的用例，結果如下，可觀察到Demo_test.py與test_demo.py兩個測驗檔案均被運行，

E:\pytestDemo>pytest
=================== test session starts =================================
platform win32 -- Python 3.7.5, pytest-5.4.1, py-1.8.1, pluggy-0.13.1
rootdir: E:\pytestDemo
collected 4 items

Demo_test.py FF                                                                                                  [ 50%]
test_demo.py ..                                                                                                  [100%]

======================= FAILURES ================================
_______________________ TestClass.test_multi _________________________

self = <pytestDemo.Demo_test.TestClass object at 0x00000190540EAA48>

    def test_multi(self):
>       assert multi(3, 3) == 6
E       assert 9 == 6
E        +  where 9 = multi(3, 3)

Demo_test.py:25: AssertionError
_________________ TestClass.test_divide _________________________

self = <pytestDemo.Demo_test.TestClass object at 0x00000190540DF208>

    def test_divide(self):
>       assert divide(3, 2) == 4
E       assert 1.5 == 4
E        +  where 1.5 = divide(3, 2)

Demo_test.py:28: AssertionError
==================== short test summary info ==========================
FAILED Demo_test.py::TestClass::test_multi - assert 9 == 6
FAILED Demo_test.py::TestClass::test_divide - assert 1.5 == 4
=================== 2 failed, 2 passed in 0.07s =======================

1.2 方式2：pytest test_*.py

執行某一個py檔案下用例【pytest 腳本名稱.py】，操作步驟及運行結果如下，可觀察到僅僅運行了Demo_test.py檔案，而test_demo.py并未被運行，

E:\pytestDemo>pytest Demo_test.py
========= test session starts ==================================
platform win32 -- Python 3.7.5, pytest-5.4.1, py-1.8.1, pluggy-0.13.1
rootdir: E:\pytestDemo
collected 2 items
Demo_test.py FF                                                                                                  [100%]

========================= FAILURES ================================
_____ TestClass.test_multi _________________________
self = <pytestDemo.Demo_test.TestClass object at 0x000001B64767ED48>
    def test_multi(self):
>       assert multi(3, 3) == 6
E       assert 9 == 6
E        +  where 9 = multi(3, 3)

Demo_test.py:25: AssertionError
________________________TestClass.test_divide ____________________________
self = <pytestDemo.Demo_test.TestClass object at 0x000001B64767EF48>
    def test_divide(self):
>       assert divide(3, 2) == 4
E       assert 1.5 == 4
E        +  where 1.5 = divide(3, 2)

Demo_test.py:28: AssertionError
===================== short test summary info =========================
FAILED Demo_test.py::TestClass::test_multi - assert 9 == 6
FAILED Demo_test.py::TestClass::test_divide - assert 1.5 == 4
================ 2 failed in 0.10s ===================

1.3 方式3：python -m pytest

通過python -m pytest運行當前目錄下的所有測驗用例檔案，

E:\pytestDemo>python -m pytest
================test session starts ====================================
platform win32 -- Python 3.7.5, pytest-5.4.1, py-1.8.1, pluggy-0.13.1
rootdir: E:\pytestDemo
collected 4 items
Demo_test.py FF                                                                                                  [ 50%]
test_demo.py ..                                                                                                  [100%]
=====================FAILURES ==========================
__________ TestClass.test_multi ____________________________________
self = <pytestDemo.Demo_test.TestClass object at 0x0000019554B8AE48>
    def test_multi(self):
>       assert multi(3, 3) == 6
E       assert 9 == 6
E        +  where 9 = multi(3, 3)

Demo_test.py:25: AssertionError
__________________TestClass.test_divide ____________________

self = <pytestDemo.Demo_test.TestClass object at 0x0000019554B4A708>
    def test_divide(self):
>       assert divide(3, 2) == 4
E       assert 1.5 == 4
E        +  where 1.5 = divide(3, 2)
Demo_test.py:28: AssertionError
===================== short test summary info ====================
FAILED Demo_test.py::TestClass::test_multi - assert 9 == 6
FAILED Demo_test.py::TestClass::test_divide - assert 1.5 == 4
=================== 2 failed, 2 passed in 0.14s ====================

1.4 節點運行

通過節點運行方式可運行某個.py檔案（模塊）里的某個函式或某個方法，如僅僅運行Demo_test.py檔案中的test_multi方法，而Demo_test.py中的test_divide不要運行，
通過“pytest Demo_test.py::TestClass::test_multi”運行后，在結果中可觀察到僅僅運行了test_multi方法，

E:\pytestDemo>pytest Demo_test.py::TestClass::test_multi
=================== test session starts ===================
platform win32 -- Python 3.7.5, pytest-5.4.1, py-1.8.1, pluggy-0.13.1
rootdir: E:\pytestDemo
collected 1 item

Demo_test.py F                                                                                                   [100%]

======================== FAILURES ======================
_____________________TestClass.test_multi _________________________
self = <pytestDemo.Demo_test.TestClass object at 0x0000015DDF3E64C8>
    def test_multi(self):
>       assert multi(3, 3) == 6
E       assert 9 == 6
E        +  where 9 = multi(3, 3)

Demo_test.py:25: AssertionError
=================== short test summary info =============================
FAILED Demo_test.py::TestClass::test_multi - assert 9 == 6
==================== 1 failed in 0.05s ===================

1.5 遇到錯誤停止測驗

Demo_test.py檔案中的test_multi與 test_divide兩個方法運行斷言，均會執行失敗，通過pytest -x Demo_test.py執行程序中，當遇到第一個方法或函式執行無法通過，則將停止運行，后面的方法或函式將不被執行，如下所示：

E:\pytestDemo>pytest -x Demo_test.py
====================== test session starts ====================
platform win32 -- Python 3.7.5, pytest-5.4.1, py-1.8.1, pluggy-0.13.1
rootdir: E:\pytestDemo
collected 2 items
Demo_test.py F
=================================== FAILURES =====================
_______________ TestClass.test_multi _____________________________
self = <pytestDemo.Demo_test.TestClass object at 0x00000208030AFD48>
    def test_multi(self):
>       assert multi(3, 3) == 6
E       assert 9 == 6
E        +  where 9 = multi(3, 3)

Demo_test.py:25: AssertionError
============================== short test summary info ==============
FAILED Demo_test.py::TestClass::test_multi - assert 9 == 6
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
============================= 1 failed in 0.06s =========================

pytest測驗用例撰寫非常簡單，pytest可以在不同的函式、包中發現用例，但pytest有如下約束，

2. 編譯器中配置pytest

Python默認自帶的單元測驗框架是unittest，因此在PyCharm編譯器中默認的單元測驗框架一般是unittest，如果想修改當前工程的單元測驗框架，可通過修改PyCharm默認的【test runner】來指定為單元測驗框架pytest，
修改路徑file->Setting->Tools->python Integrated Tools>Default test runner-> pytest，如圖所示，

圖 PyTest的設定