Running PyTest in a Nox Environment within PyCharm

What will you learn?

In this tutorial, you will learn how to efficiently run PyTest within a Nox environment directly from PyCharm. By the end of this guide, you will have gained insight into setting up and executing your tests using PyTest in a Nox-managed environment without leaving the comfort of PyCharm.

Introduction to Problem and Solution

Navigating through the process of running PyTest within a Nox environment can initially appear challenging. However, with the guidance provided here, you’ll be able to seamlessly integrate these tools for an enhanced testing experience.

A Brief Overview

Nox is a robust automation tool in Python that simplifies managing multiple virtual environments, making it ideal for testing across various Python versions or dependency sets. On the other hand, PyTest is a mature full-featured Python testing tool that aids in writing better programs. Combining these tools can significantly streamline your testing workflow.

Diving Into The Solution

To achieve our goal, we will first ensure that both Nox and PyTest are correctly installed and configured in our project. Then, we’ll set up a script defining our session for running tests with PyTest. Finally, we’ll configure PyCharm to recognize this setup and allow us to execute tests seamlessly within its IDE.


  1. Ensure Nox and PyTest are installed:

    pip install nox pytest
    # Copyright PHD
  2. Create at your project root with the following content:

    import nox
    def tests(session):
    # Copyright PHD
  3. In PyCharm, navigate to File > Settings > Tools > External Tools.

  4. Add a new external tool configuration with the following details:

    • Name: Run Nox Tests
    • Program: Path/to/your/python.exe (or just nox if available globally)
    • Arguments: -e tests
    • Working directory: $ProjectFileDir$

With these steps, you’ve set up an external tool configuration in PyCharm for running Nox sessions directly from the IDE.


The process bridges your development environment (PyCharm) with your test automation setup (Nox + PyTest). By defining specific sessions in, we instruct NoX on preparing the testing environment � installing dependencies as needed and executing pytest against our codebase.

Configuring this as an external tool in PyCharm provides instant access to predefined tasks without switching contexts or leaving the IDE.

This approach enhances productivity and maintains consistency across development environments as all required actions are codified within scripts (

  1. How do I install NoX?

  2. To install NoX, run:

  3. pip install nox
  4. # Copyright PHD
  5. How can I specify different Python versions for my tests?

  6. Edit your‘s session decorator by specifying Python versions like:

  7. @nox.session(python=["3.6", "3.7"])
  8. # Copyright PHD
  9. Can I run specific test files using this method?

  10. Yes! Modify arguments passed into within your tests function:

  11."pytest", "path/to/")
  12. # Copyright PHD
  13. What if I need additional packages during test runs?

  14. Include more .install() calls before running pytest in your nox session definition.

  15. session.install("requests")
  16. # Copyright PHD
  17. Can I pass arguments from Pycharm’s external tools configurations directly into pytest?

  18. Due to their static declaration nature, modifying either your noxE file or creating separate sessions is necessary for different configurations currently.


Integrating NoX with pytest inside of PYCHARM streamlines local development by providing automated validation against defined criteria ensuring high code quality throughout application development lifecycle. This setup fosters collaboration among team members who benefit from shared consistent understanding of requirements for success.

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