It's no exaggeration to say that this is the most user-friendly basic tutorial of pytest I've ever seen

Pytest brief introduction

Pytest is a mature full-featured Python testing tool that helps you write better programs.The pytest framework makes it easy to write small tests, yet scales to support complex functional testing for applications and libraries.

Through the introduction of the official website, we can learn ,Pytest Is a very mature full-featured python The test framework , It mainly has the following characteristics ：

Simple, flexible and easy to use
Support parameterization
Support simple unit testing and complex functional testing , It can also be used for automated testing
There are many third-party plug-ins , And you can customize the extension
Of test cases skip and xfail Handle
It can be very good and Jenkins Integrate
Support run by Nose、UnitTest Test cases written

Pytest install

1. Use it directly pip Command to install ：

pip install -U pytest    # -U Yes, if installed, it will automatically upgrade to the latest version 

2. Verify installation results ：

pytest --version    #  Show the currently installed version 


C:\Users\edison>pytest --version
pytest 6.2.5

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3. stay pytest In the test framework , The following constraints apply ：

The test file name should conform to test_.py or _test.py Format （ for example test_min.py）
The test class should be Test start , And cannot have init Method
In a single test class , Can contain one or more test_ Initial function

Pytest The test execution

pytest Testing is relatively simple , Let's look at an example ：

import pytest    #  Import pytest package 


def test_001():    #  Function to test_ start 
    print("test_01")


def test_002():
    print("test_02")


if __name__ == '__main__':
    pytest.main(["-v","test_1214.py"])    #  call pytest Of main Function execution test 

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 Here we define two test functions , Print the result directly , Now perform the test ：

============================= test session starts =============================
platform win32 -- Python 3.8.0, pytest-6.2.5, py-1.11.0, pluggy-1.0.0 -- D:\Code\venv\Scripts\python.exe
cachedir: .pytest_cache
rootdir: D:\Code
collecting ... collected 2 items


test_1214.py::test_001 PASSED                                            [ 50%]
test_1214.py::test_002 PASSED                                            [100%]


============================== 2 passed in 0.11s ==============================


Process finished with exit code 0

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The output shows how many cases have been executed 、 Corresponding test module 、 Number of passes and execution time .

Test class main function

pytest.main(["-v","test_1214.py"])

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adopt python Code execution pytest.main()：

Direct execution pytest.main() 【 Automatically find the current directory , With test_ A document that begins with or with _test At the end of the py file 】;
Set up pytest The execution parameters of pytest.main([‘–html=./report.html’,‘test_login.py’])【 perform test_login.py file , And generate html Report in format 】.

main() Execution parameters and plug-in parameters can be passed in parentheses , adopt [] Segmentation ,[] Multiple parameters in the pass through ‘ comma ,’ Segmentation ：

Run all use cases under the directory and sub packages pytest.main([‘ Directory name ’])
Run all use cases of the specified module pytest.main([‘test_reg.py’])
Run the specified module, specified class, specified use case pytest.main([‘test_reg.py::TestClass::test_method’]) Colon division

-m=xxx: Run tagged use cases

-reruns=xxx： Failed to rerun

-q: Quiet mode , Do not output environment information

-v: Rich information mode , Output more detailed use case execution information

-s: Displays the... In the program print/logging Output

–resultlog=./log.txt Generate log

–junitxml=./log.xml Generate xml The report

assert methods

pytest Assertions mainly use Python Native assertion methods , There are mainly the following ：

== The content and type must be equal at the same time
in Actual results include expected results
is Assert that the two values before and after are equal
import pytest # Import pytest package

def add(x,y):    #  Define to test_ Start function 
    return x + y


def test_add():
    assert add(1,2) == 3    #  Assert success 


str1 = "Python,Java,Ruby"
def test_in():
    assert "PHP" in str1    #  Assertion failed 


if __name__ == '__main__':
    pytest.main(["-v","test_pytest.py"])    #  call main Function execution test 

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============================= test session starts =============================
platform win32 -- Python 3.8.0, pytest-6.2.5, py-1.11.0, pluggy-1.0.0 -- D:\Code\venv\Scripts\python.exe
cachedir: .pytest_cache
rootdir: D:\Code
collecting ... collected 2 items


test_pytest.py::test_add PASSED                                          [ 50%]
test_pytest.py::test_in FAILED                                           [100%]


================================== FAILURES ===================================
___________________________________ test_in ___________________________________


    def test_in():
>       assert "PHP" in str1
E       AssertionError: assert 'PHP' in 'Python,Java,Ruby'


test_pytest.py:11: AssertionError
=========================== short test summary info ===========================
FAILED test_pytest.py::test_in - AssertionError: assert 'PHP' in 'Python,Java...
========================= 1 failed, 1 passed in 0.18s =========================


Process finished with exit code 0

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You can see that the reason for the error is clearly pointed out in the operation result “AssertionError”, because PHP be not in str1 in .

A detailed explanation of common orders

1. Run the specified case ：

if __name__ == '__main__':
    pytest.main(["-v","-s","test_1214.py"])

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2. Run all use cases in the current folder, including subfolders ：

if __name__ == '__main__':
    pytest.main(["-v","-s","./"])

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3. Run the specified folder （code All use cases in the directory ）：

if __name__ == '__main__':
    pytest.main(["-v","-s","code/"])

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4. Use cases are specified in the run module （ In the running module test_add Use cases ）：

if __name__ == '__main__':
    pytest.main(["-v","-s","test_pytest.py::test_add"])

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5. Maximum number of execution failures .

Use expressions "–maxfail=num" To achieve （ Be careful ： There can be no spaces in the expression ）, Indicates that the total number of use case failures is equal to num Stop running when .

6. The error message is displayed on one line .

In the actual project, if many use cases fail to execute , Checking the error message will be troublesome . Use "–tb=line" command , It can solve this problem very well .
Interface call

Write an interface to query user information locally , adopt pytest To call , And make interface assertions .

# -*- coding: utf-8 -*-
 import pytest
 import requests
 
 def test_agent():
     r = requests.post(
         url="http://127.0.0.1:9000/get_user",
         data={
    
             "name": " Wu lei ",
            "sex": 1
        },
        headers={
    "Content-Type": "application/json"}
    )
    print(r.text)
    assert r.json()['data']['retCode'] == "00" and r.json()['data']['retMsg'] == " Successful call "
if __name__ == "__main__":
    pytest.main(["-v","test_api.py"])

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