1. 概述

pytest是一個(gè)非常成熟的全功能的Python測試框架，主要特點(diǎn)有以下幾點(diǎn)：

• 1、簡單靈活，容易上手，文檔豐富；
• 2、支持參數(shù)化，可以細(xì)粒度地控制要測試的測試用例；
• 3、能夠支持簡單的單元測試和復(fù)雜的功能測試，還可以用來做selenium/appnium等自動化測試、接口自動化測試（pytest+requests）;
• 4、pytest具有很多第三方插件，并且可以自定義擴(kuò)展，比較好用的如pytest-selenium（集成selenium）、pytest-html（完美html測試報(bào)告生成）、pytest-rerunfailures（失敗case重復(fù)執(zhí)行）、pytest-xdist（多CPU分發(fā)）等；
• 5、測試用例的skip和xfail處理；
• 6、可以很好的和CI工具結(jié)合，例如jenkins

2. 使用介紹

2.1. 安裝

pip install pytest

2.2. 示例代碼

編寫規(guī)則

編寫pytest測試樣例非常簡單，只需要按照下面的規(guī)則：

• 測試文件以test_開頭（以_test結(jié)尾也可以）
• 測試類以Test開頭，并且不能帶有 init 方法
• 測試函數(shù)以test_開頭
• 斷言使用基本的assert即可

pytest1.py

# -*- coding:utf-8 -*-
import pytest@pytest.fixture(scope='function')
def setup_function(request): def teardown_function(): print("teardown_function called.") request.addfinalizer(teardown_function) # 此內(nèi)嵌函數(shù)做teardown工作 print('setup_function called.') @pytest.fixture(scope='module') def setup_module(request): def teardown_module(): print("teardown_module called.") request.addfinalizer(teardown_module) print('setup_module called.') @pytest.mark.website def test_1(setup_function): print('Test_1 called.') def test_2(setup_module): print('Test_2 called.') def test_3(setup_module): print('Test_3 called.') assert 2==1+1 # 通過assert斷言確認(rèn)測試結(jié)果是否符合預(yù)期 

fixture的scope參數(shù)

scope參數(shù)有四種，分別是'function','module','class','session'，默認(rèn)為function。

• function：每個(gè)test都運(yùn)行，默認(rèn)是function的scope
• class：每個(gè)class的所有test只運(yùn)行一次
• module：每個(gè)module的所有test只運(yùn)行一次
• session：每個(gè)session只運(yùn)行一次

setup和teardown操作

• setup，在測試函數(shù)或類之前執(zhí)行，完成準(zhǔn)備工作，例如數(shù)據(jù)庫鏈接、測試數(shù)據(jù)、打開文件等
• teardown，在測試函數(shù)或類之后執(zhí)行，完成收尾工作，例如斷開數(shù)據(jù)庫鏈接、回收內(nèi)存資源等
• 備注：也可以通過在fixture函數(shù)中通過yield實(shí)現(xiàn)setup和teardown功能

2.3. 測試結(jié)果

如何執(zhí)行

• pytest # run all tests below current dir
• pytest test_mod.py # run tests in module file test_mod.py
• pytest somepath # run all tests below somepath like ./tests/
• pytest -k stringexpr # only run tests with names that match the
  # the "string expression", e.g. "MyClass and not method"
  # will select TestMyClass.test_something
  # but not TestMyClass.test_method_simple
• pytest test_mod.py::test_func # only run tests that match the "node ID",
  # e.g "test_mod.py::test_func" will be selected
  # only run test_func in test_mod.py

通過pytest.mark對test方法分類執(zhí)行

通過@pytest.mark控制需要執(zhí)行哪些feature的test，例如在執(zhí)行test前增加修飾@pytest.mark.website

• 通過 -m "website" 執(zhí)行有website標(biāo)記的test方法

$ pytest  -v -m "website" pytest1.py
============================================================================== test session starts ===============================================================================
platform linux2 -- Python 2.7.14, pytest-3.0.0, py-1.5.2, pluggy-0.3.1 -- /home/kevin/soft/anaconda2/bin/python cachedir: .cache Using --randomly-seed=1522925202 rootdir: /home/kevin/learn/python-web/tox/case2, inifile: plugins: randomly-1.0.0, mock-1.2, cov-2.0.0 collected 3 items pytest1.py::test_1 PASSED ============================================================================= pytest-warning summary ============================================================================= WC1 None pytest_funcarg__cov: declaring fixtures using "pytest_funcarg__" prefix is deprecated and scheduled to be removed in pytest 4.0. Please remove the prefix and use the @pytest.fixture decorator instead. =============================================================================== 2 tests deselected =============================================================================== =========================================================== 1 passed, 2 deselected, 1 pytest-warnings in 0.00 seconds ============================================================ 

• 通過 -m "not website" 執(zhí)行沒有website標(biāo)記的test方法

$ pytest  -v -m "not website" pytest1.py
============================================================================== test session starts ===============================================================================
platform linux2 -- Python 2.7.14, pytest-3.0.0, py-1.5.2, pluggy-0.3.1 -- /home/kevin/soft/anaconda2/bin/python cachedir: .cache Using --randomly-seed=1522925192 rootdir: /home/kevin/learn/python-web/tox/case2, inifile: plugins: randomly-1.0.0, mock-1.2, cov-2.0.0 collected 3 items pytest1.py::test_3 PASSED pytest1.py::test_2 PASSED ============================================================================= pytest-warning summary ============================================================================= WC1 None pytest_funcarg__cov: declaring fixtures using "pytest_funcarg__" prefix is deprecated and scheduled to be removed in pytest 4.0. Please remove the prefix and use the @pytest.fixture decorator instead. =============================================================================== 1 tests deselected =============================================================================== =========================================================== 2 passed, 1 deselected, 1 pytest-warnings in 0.00 seconds ============================================================ 

Console參數(shù)介紹

• -v 用于顯示每個(gè)測試函數(shù)的執(zhí)行結(jié)果
• -q 只顯示整體測試結(jié)果
• -s 用于顯示測試函數(shù)中print()函數(shù)輸出
• -x, --exitfirst, exit instantly on first error or failed test
• -h 幫助

Case 1

$ pytest -v pytest1.py
============================================================================== test session starts ===============================================================================
platform linux2 -- Python 2.7.14, pytest-3.0.0, py-1.5.2, pluggy-0.3.1 -- /home/kevin/soft/anaconda2/bin/python cachedir: .cache Using --randomly-seed=1522920341 rootdir: /home/kevin/learn/python-web/tox/case2, inifile: plugins: randomly-1.0.0, mock-1.2, cov-2.0.0 collected 3 items pytest1.py::test_1 PASSED pytest1.py::test_3 PASSED pytest1.py::test_2 PASSED ============================================================================= pytest-warning summary ============================================================================= WC1 None pytest_funcarg__cov: declaring fixtures using "pytest_funcarg__" prefix is deprecated and scheduled to be removed in pytest 4.0. Please remove the prefix and use the @pytest.fixture decorator instead. ================================================================== 3 passed, 1 pytest-warnings in 0.01 seconds =================================================================== 

Case 2

$ pytest -s pytest1.py
============================================================================== test session starts ===============================================================================
platform linux2 -- Python 2.7.14, pytest-3.0.0, py-1.5.2, pluggy-0.3.1 Using --randomly-seed=1522920508 rootdir: /home/kevin/learn/python-web/tox/case2, inifile: plugins: randomly-1.0.0, mock-1.2, cov-2.0.0 collected 3 items pytest1.py setup_function called. Test_1 called. .teardown_function called. setup_module called. Test_2 called. .Test_3 called. .teardown_module called. ============================================================================= pytest-warning summary ============================================================================= WC1 None pytest_funcarg__cov: declaring fixtures using "pytest_funcarg__" prefix is deprecated and scheduled to be removed in pytest 4.0. Please remove the prefix and use the @pytest.fixture decorator instead. ================================================================== 3 passed, 1 pytest-warnings in 0.01 seconds =================================================================== 

3. 擴(kuò)展插件

3.1. 測試報(bào)告

安裝與樣例

pip install pytest-cov # 計(jì)算pytest覆蓋率，支持輸出多種格式的測試報(bào)告
pytest --cov-report=html --cov=./ test_code_target_dir

Console參數(shù)介紹

• --cov=[path], measure coverage for filesystem path (multi-allowed), 指定被測試對象，用于計(jì)算測試覆蓋率
• --cov-report=type, type of report to generate: term, term-missing, annotate, html, xml (multi-allowed), 測試報(bào)告的類型
• --cov-config=path, config file for coverage, default: .coveragerc, coverage配置文件
• --no-cov-on-fail, do not report coverage if test run fails, default: False，如果測試失敗，不生成測試報(bào)告
• --cov-fail-under=MIN, Fail if the total coverage is less than MIN. 如果測試覆蓋率低于MIN，則認(rèn)為失敗

Console Result

---------------------------------------------------------------- coverage: platform linux2, python 2.7.14-final-0 ---------------------------------------------------------------- Name Stmts Miss Cover -------------------------------- pytest1.py 18 0 100% 

Html Result

image.png

3.2. 測試順序隨機(jī)

pip install pytest-randomly

3.3. 分布式測試

pip install pytest-xdist

3.4. 出錯(cuò)立即返回

pip install pytest-instafail

4. 參考

• python的測試工具大全
  https://wiki.python.org/moin/PythonTestingToolsTaxonomy

• python主流的測試工具橫向比較
  http://docs.python-guide.org/en/latest/writing/tests/
  http://pythontesting.net/test-podcast/

• python單元測試框架pytest簡介
  https://blog.csdn.net/liuchunming033/article/details/46501653

作者：紅薯愛帥
鏈接：https://www.jianshu.com/p/a754e3d47671
來源：簡書
簡書著作權(quán)歸作者所有，任何形式的轉(zhuǎn)載都請聯(lián)系作者獲得授權(quán)并注明出處。

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