1. 概述
pytest是一个非常成熟的全功能的Python测试框架，主要特点有以下几点：
- 1、简单灵活，容易上手，文档丰富；
- 2、支持参数化，可以细粒度地控制要测试的测试用例；
- 3、能够支持简单的单元测试和复杂的功能测试，还可以用来做selenium/appnium等自动化测试、接口自动化测试（pytest+requests）;
- 4、pytest具有很多第三方插件，并且可以自定义扩展，比较好用的如pytest-selenium（集成selenium）、pytest-html（完美html测试报告生成）、pytest-rerunfailures（失败case重复执行）、pytest-xdist（多CPU分发）等；
- 5、测试用例的skip和xfail处理；
- 6、可以很好的和CI工具结合，例如jenkins
2. 使用介绍
2.1. 安装
pip install pytest
2.2. 示例代码
编写规则
编写pytest测试样例非常简单，只需要按照下面的规则：
- 测试文件以test_开头（以_test结尾也可以）
- 测试类以Test开头，并且不能带有 init 方法
- 测试函数以test_开头
- 断言使用基本的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) # 此内嵌函数做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 # 通过assert断言确认测试结果是否符合预期
fixture的scope参数
scope参数有四种，分别是'function','module','class','session'，默认为function。
- function：每个test都运行，默认是function的scope
- class：每个class的所有test只运行一次
- module：每个module的所有test只运行一次
- session：每个session只运行一次
setup和teardown操作
- setup，在测试函数或类之前执行，完成准备工作，例如数据库链接、测试数据、打开文件等
- teardown，在测试函数或类之后执行，完成收尾工作，例如断开数据库链接、回收内存资源等
- 备注：也可以通过在fixture函数中通过yield实现setup和teardown功能
2.3. 测试结果
如何执行
- 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
通过pytest.mark对test方法分类执行
通过@pytest.mark控制需要执行哪些feature的test，例如在执行test前增加修饰@pytest.mark.website
- 通过 -m "website" 执行有website标记的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 ============================================================
- 通过 -m "not website" 执行没有website标记的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参数介绍
- -v 用于显示每个测试函数的执行结果
- -q 只显示整体测试结果
- -s 用于显示测试函数中print()函数输出
- -x, --exitfirst, exit instantly on first error or failed test
- -h 帮助
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. 扩展插件
3.1. 测试报告
安装与样例
pip install pytest-cov # 计算pytest覆盖率，支持输出多种格式的测试报告
pytest --cov-report=html --cov=./ test_code_target_dir
Console参数介绍
- --cov=[path], measure coverage for filesystem path (multi-allowed), 指定被测试对象，用于计算测试覆盖率
- --cov-report=type, type of report to generate: term, term-missing, annotate, html, xml (multi-allowed), 测试报告的类型
- --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，如果测试失败，不生成测试报告
- --cov-fail-under=MIN, Fail if the total coverage is less than MIN. 如果测试覆盖率低于MIN，则认为失败
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. 测试顺序随机
pip install pytest-randomly
3.3. 分布式测试
pip install pytest-xdist
3.4. 出错立即返回
pip install pytest-instafail
4. 参考
python的测试工具大全
https://wiki.python.org/moin/PythonTestingToolsTaxonomypython主流的测试工具横向比较
http://docs.python-guide.org/en/latest/writing/tests/
http://pythontesting.net/test-podcast/python单元测试框架pytest简介
https://blog.csdn.net/liuchunming033/article/details/46501653
