Pytest运行测试用例的多种方式

Pytest提供了多样化的方式来运行和调试测试用例，本文介绍一些比较常用的方式。
pytest是如何识别测试用例的呢？它默认使用检查以test_ .py 或test.py命名的文件名，在文件内部查找以test打头的方法或函数，并执行它们。
下面是Pytest的官网的一些测试例子，本文用它来进行不同的Pytest运行。
首先安装好Python和Pytest，新建一个test_pytest_markers.py，在Terminal里面可以尝试以下不同的运行方式。

#Below are test_pytest_markers.py 
# content of test_server.py

import pytest

@pytest.mark.webtest

def test_send_http():

pass # perform some webtest test for your app

def test_something_quick():

pass

def test_another():

pass

class TestClass:

def test_method(self):

pass

1. Pytest Marker 机制

对于Pytest的测试用例，可以在每一个测试用例加一个marker，比如pytest运行的时就只运行带有该marker的测试用例，比如下面的@pytest.mark.webtest。
在我们的实际项目中，我们通常把为每个feature建立相应的marker，用于测试时进行不同条件的挑选。
Pytest还支持一个测试用例有多个marker，这个在后续会把相应的实践加入进来。
测试结果如下，只挑选了测试用例带有webtest marker的运行。

C:\Users\yatyang\PycharmProjects\pytest_example>pytest -v -m "webtest" test_pytest_markers.py
============================= test session starts =============================
platform win32 -- Python 2.7.13, pytest-3.0.6, py-1.4.32, pluggy-0.4.0 -- C:\Python27\python.exe
cachedir: .cache
rootdir: C:\Users\yatyang\PycharmProjects\pytest_example, inifile:
collected 4 items 

test_pytest_markers.py::test_send_http PASSED

============================= 3 tests deselected ==============================
=================== 1 passed, 3 deselected in 0.04 seconds ====================

同样的，也可以只挑选了测试用例中不带有webtest marker的运行。

C:\Users\yatyang\PycharmProjects\pytest_example>pytest -v -m "not webtest" test_pytest_markers.py
============================= test session starts =============================
platform win32 -- Python 2.7.13, pytest-3.0.6, py-1.4.32, pluggy-0.4.0 -- C:\Python27\python.exe
cachedir: .cache
rootdir: C:\Users\yatyang\PycharmProjects\pytest_example, inifile:
collected 4 items 

test_pytest_markers.py::test_something_quick PASSED
test_pytest_markers.py::test_another PASSED
test_pytest_markers.py::TestClass::test_method PASSED

============================= 1 tests deselected ==============================

2. 选择运行特定的某个测试用例

你可以按照某个测试用例的的模块，类或函数来选择你要运行的case，比如下面的方式就适合一开始在调试单个测试用例的时候。

C:\Users\yatyang\PycharmProjects\pytest_example>pytest -v test_pytest_markers.py::TestClass::test_method
============================= test session starts =============================
platform win32 -- Python 2.7.13, pytest-3.0.6, py-1.4.32, pluggy-0.4.0 -- C:\Python27\python.exe
cachedir: .cache
rootdir: C:\Users\yatyang\PycharmProjects\pytest_example, inifile:
collected 5 items 

test_pytest_markers.py::TestClass::test_method PASSED

========================== 1 passed in 0.03 seconds ===========================

3. 选择运行特定的某个类

比如你想单独运行下某个类的所有测试用例，可以按照如下操作。

C:\Users\yatyang\PycharmProjects\pytest_example>pytest -v test_pytest_markers.py::TestClass
============================= test session starts =============================
platform win32 -- Python 2.7.13, pytest-3.0.6, py-1.4.32, pluggy-0.4.0 -- C:\Python27\python.exe
cachedir: .cache
rootdir: C:\Users\yatyang\PycharmProjects\pytest_example, inifile:
collected 4 items 

test_pytest_markers.py::TestClass::test_method PASSED

========================== 1 passed in 0.04 seconds ===========================

4 多种组合

比如下面，你可以进行以上两种方式的组合挑选你需要运行的测试用例。

C:\Users\yatyang\PycharmProjects\pytest_example>pytest -v test_pytest_markers.py::TestClass test_pytest_markers.py::test_send_http
============================= test session starts =============================
platform win32 -- Python 2.7.13, pytest-3.0.6, py-1.4.32, pluggy-0.4.0 -- C:\Python27\python.exe
cachedir: .cache
rootdir: C:\Users\yatyang\PycharmProjects\pytest_example, inifile:
collected 8 items 

test_pytest_markers.py::TestClass::test_method PASSED
test_pytest_markers.py::test_send_http PASSED

========================== 2 passed in 0.06 seconds ===========================

5 用-k进行关键字匹配来运行测试用例名字子串

比如用-k选择测试用例的名字中只带有http关键字的运行。

C:\Users\yatyang\PycharmProjects\pytest_example>pytest -v -k http test_pytest_markers.py
============================= test session starts =============================
platform win32 -- Python 2.7.13, pytest-3.0.6, py-1.4.32, pluggy-0.4.0 -- C:\Python27\python.exe
cachedir: .cache
rootdir: C:\Users\yatyang\PycharmProjects\pytest_example, inifile:
collected 4 items 

test_pytest_markers.py::test_send_http PASSED

============================= 3 tests deselected ==============================
=================== 1 passed, 3 deselected in 0.12 seconds ====================

Reference

1. http://docs.pytest.org/en/latest/example/markers.html