The 7 Best Frameworks for Integration and Unit Testing in Python


The simplicity of Python makes it one of the best programming languages ​​for writing automated tests. The language offers a few software testing frameworks to help you test more efficiently.

Whether you want end-to-end testing, load and stress testing, or more, these are the best Python-based software testing frameworks.


Pytest is a simple testing framework written in Python and for Python. Why should you use it for testing? It has an easy learning curve and is a go-to framework for unit and integration testing. It also supports class inheritance from unittest.

One of the strengths of the framework is that it provides a cleaner and shorter way to write tests in Python. For example, validating code output is as easy as calling a to affirm keyword. If you want to run multiple tests simultaneously, Pytest saves you time with its headless parallel testing feature.

Pytest also supports command line execution of test suites. It’s as simple as running the pytest command from the test folder terminal. You don’t have to worry about test files, because the framework detects them automatically.

However, the command also works with the file declaration. So you can also invoke Pytest with a filename:


Running a test file with Pytest produces user-friendly output that traces the steps of the test and tells you where the fault is:

2. Playwright

The dramaturge framework is Microsoft’s offering to the software testing community. While many frameworks only work with headless tests, Playright supports both headless and headed modes. It is one of the best frameworks for testing UI, with support for Firefox and Chromium based browsers like Edge and Chrome.

In terms of features, Playwright is close to Selenium. It matches the latter for cloud-based parallel testing and orchestration tools. But it beats Selenium with its API testing feature. However, Playwright’s parallel testing can be tricky because its event loop only runs one test capability by default. However, you can find your way around with proper use of Python loops.

If you want to go codeless, you can use Playwright’s codegen to write test code dynamically. It generates a language-specific test file when you interact with the DOM. Its selector builder also allows you to easily select web elements by simply hovering over them without having to inspect the DOM.

Playwright has auto-wait by default. So it pauses for the DOM to load before executing test cases. At the time of writing, the playwright framework supports JavaScript, TypeScript, Java, and .NET in addition to Python.

3. Selenium

Selenium is one of the most widely used automation testing frameworks with good community support. Unlike Playwright, it does not offer API testing capability. So this is not the framework to test the main logic. But it provides both Chromium-based and non-Chromium-based browser drivers to evaluate and validate the UI.

The framework has more support for programming languages ​​and is more versatile in general web automation. It also supports cloud grid capability to orchestrate test cases in parallel. It is therefore an excellent choice for cross-browser and cross-platform testing.

Selenium has a set of dedicated selectors that let you interact with the UI as a regular user. And if you need a dose of UI action assertion, you can inherit it from the unittest class. Selenium also has an IDE extension for Chrome and Firefox. This offers recording and playback testing. But unlike Playwright’s codegen, it does not generate test code.

4. Bots

Robot is an open-source, keyword-based Python testing framework. All in all, this makes test automation as easy as possible. Although you have to write code for test cases in other frameworks, that’s plain English in Robot. It is therefore useful for writing more user-friendly test cases.

Its strength lies in acceptance testing, to ensure that the software meets the specified criteria. Beyond testing, it also offers general robotic automation tools to automate UI tasks.

Getting started with the Robot framework is easy; you can create a set of tasks written in simple human language. Then prepare test cases for each in separate files. Robot provides few testing features, but you can extend it with other testing libraries. For example, you can combine it with Selenium to add browser functionality to UI testing.


Doctest is a built-in Python testing library that lets you document your code while you test. It is one of the best choices for running unit tests. But it also supports UI component testing. The library is intuitive, reading docstrings from your code and validating the expected output.

Doctest works by checking a function against a defined output. It only generates an error and returns the correctly calculated output if the expected result is wrong. The test output in Doctest is clean. If you’re testing on multiple inputs, for example, it gives a detailed failure report, including where the code is failing.

A test piece documented by Doctest looks like this, for example:

def findFirst(text):
Given a string, return the first alphabet
:param: string
>>> findFirst("Idowu")
return text[0].upper()
if __name__=="__main__":
import doctest

The test documented above fails because we expect a you, but the calculated result is I In place:

6. Unit testing

Unittest provides one of the most structured ways to write unit tests. It supports object-oriented programming by default. It encapsulates test cases in dedicated classes and executes them in an event loop. With that in mind, unittest is a great choice if you prefer to structure your tests in a page object model.

Unittest does not offer UI testing by default. But you can combine it with another testing framework like Selenium to get multiple browser features. You can also run parallel tests with unittest when paired with cloud grid supported frameworks. So, you can leverage its power in end-to-end integration and testing.

When combined with Selenium, for example, you can check an expected output against a component’s result using the legacy assert keyword. However, unlike Pytest, you’ll probably write more code in unittest because its assertion invocation is more hard-coded.

7. Nose2

Nose2 is closely related to Pytest in terms of functionality. However, it inherits its basic properties from the unittest framework. Like Pytest, you can use it as a tester for test cases written in other frameworks like Selenium or unittest.

It supports unit and integration testing. So whether you want to test the user interface or check the functions of your code, Nose2 provides all the necessary utilities.

It also accepts parameterized tests. This involves inserting test parameters such as browsers and test platforms into a decorator. You can then access each parameter in the body of the code. This makes Nose2 one of the best frameworks for running parallel cross-browser tests on cloud grids.

Test your program and release quality software

Testing is a good programming practice that helps you detect and remove bugs before public release. While some testing frameworks are primarily Python-based, others support multiple programming languages.

While it’s best to keep unit tests in your development language, they can be more language independent. Feel free to use any of these Python testing frameworks accordingly.


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