Скачать или смотреть Troubleshooting Import Issues in Python: The Case of ImportError

Learn how to resolve the `ImportError: attempted relative import with no known parent package` error in Python. This guide offers clear solutions and context to ensure your imports work seamlessly!
---
This video is based on the question https://stackoverflow.com/q/68187340/ asked by the user 'Adrian Edelen' ( https://stackoverflow.com/u/14517864/ ) and on the answer https://stackoverflow.com/a/68187424/ provided by the user 'Luu Duc Anh' ( https://stackoverflow.com/u/10048611/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: importing class from another file gives error when working and no error when not working

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Troubleshooting Import Issues in Python: The Case of ImportError

When importing classes from another Python file, you may occasionally encounter some frustrating errors. One common problem is the ImportError: attempted relative import with no known parent package. This error can occur when you try to run your main Python script, but the imports aren’t working as expected. In this guide, we’ll discuss this specific issue and offer a solution that can help you successfully import your classes without any errors.

Understanding the ImportError

Let’s set the scene with a quick overview of the situation. You have a project structured like this:

B:\Programming\Python\RaceDash\src\UIModules\Menus.py (where your class MainMenus is defined)

B:\Programming\Python\RaceDash\src\Main.py (your main Python file)

B:\Programming\Python\RaceDash\src\UIModules__init__.py (to make UIModules a package)

You’re trying to import the MainMenus class into your Main.py file using a relative import:

[[See Video to Reveal this Text or Code Snippet]]

However, when you run your program, you encounter the following error:

[[See Video to Reveal this Text or Code Snippet]]

Why This Error Occurs

This error arises because Python cannot determine the package structure when you run the script directly. Relative imports (indicated by the leading dot) depend on the script being run in a module context. When executed from the command line, the current script doesn't recognize its context within a package.

If you remove the leading dot, you receive an error indicating that the import could not be resolved, which is because the absolute import does not include the package namespace necessary for Python to locate your module.

Solution: Setting Up the PYTHONPATH

To resolve this issue, you can modify your environment’s PYTHONPATH to include the directory where your project resides. This allows Python to recognize the necessary package structure and successfully import your classes. Here’s how you can do this:

Steps to Fix the Issue

Set the PYTHONPATH:
You need to add your project's root directory to the PYTHONPATH. You can do this by running the following command in your terminal or command prompt:

[[See Video to Reveal this Text or Code Snippet]]

Note: If you're using Windows Command Prompt, use the following command instead:

[[See Video to Reveal this Text or Code Snippet]]

Run Your Script:
After setting the PYTHONPATH, run your Python script with:

[[See Video to Reveal this Text or Code Snippet]]

Expected Outcome

After following the above steps, your relative import should work correctly, and you should no longer see the ImportError. Additionally, you’ll regain the Intellisense features in your code editor, allowing for better code completion and suggestions.

Conclusion

Dealing with import errors in Python can be challenging, but understanding how Python's import system works is key to resolving these issues. By setting your PYTHONPATH correctly, you can eliminate the common import errors and make the most of your coding experience!

Keeping your environment configured properly will save you time and frustration in the long run. Happy coding!