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学习pytest 好的方法（网络整理收藏）

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第一部分

  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

  • 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 ===================================================================
  1. 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

pytest1.py      18      0   100%

Html Result

学习pytest 好的方法（网络整理收藏）

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

  1. 参考

  2. python的测试工具大全
    https://wiki.python.org/moin/PythonTestingToolsTaxonomy

  3. python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/
  4. python单元测试框架pytest简介
    https://blog.csdn.net/liuchunming033/article/details/46501653

转账链接：https://www.jianshu.com/p/a754e3d47671

Original: https://blog.csdn.net/qq_40024178/article/details/119166551
Author: 海阔天空_2018
Title: 学习pytest 好的方法（网络整理收藏）

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