Resolving ModuleNotFoundError with openpyxl in PyInstaller Executables

Learn how to fix the `ModuleNotFoundError` related to `openpyxl` when using PyInstaller to create executable files from your Python scripts.
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Resolving ModuleNotFoundError with openpyxl in PyInstaller Executables

Creating standalone executables from Python scripts can save time and effort, especially when you need to share your application with users who may not have Python installed. However, if you encounter errors during the build process, such as ModuleNotFoundError, it can be a frustrating experience. In this guide, we will dive into a common issue that arises when using PyInstaller—the failure to find key modules such as openpyxl in your compiled executable.

The Problem: ModuleNotFoundError

Recently, a user encountered an issue where PyInstaller failed to locate the openpyxl module after transitioning their code from a pip environment to a conda environment. The error trace provided indicated a failure with the following message:

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

This error was thrown when they attempted to execute the .exe file created with PyInstaller, despite running the script without error in the conda environment itself.

Understanding the Cause

The issue arose because the versions of openpyxl in the two distinct environments were different:

Pip Environment: openpyxl version 3.0.9

Conda Environment: openpyxl version 3.0.10

Since the higher version of openpyxl could potentially contain breaking changes or alterations in structure, PyInstaller was unable to locate certain components when creating the executable.

The Solution: Downgrade the Package

The simplest and most effective solution to this problem was to downgrade the openpyxl package in the conda environment to match the version used in the pip environment. Here's how you can do it:

Steps to Downgrade OpenPyXL

Check Current Package Version: First, confirm the currently installed version of openpyxl.

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

Downgrade the Package: If it's a higher version, you can downgrade it using the following command:

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

Rebuild Your Executable: After downgrading, rebuild your executable using PyInstaller:

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

Result

Once the package is downgraded and the executable is rebuilt, you should find that the ModuleNotFoundError no longer occurs. The application will compile and run successfully, allowing you to share it without any hitches.

Conclusion

Transitioning code from one environment to another is sometimes necessary, especially when needing specific libraries like geopandas, fiona, and gdal. However, it's crucial to ensure that packages such as openpyxl are compatible across those environments. By keeping your package versions consistent, you can avoid common pitfalls like the ModuleNotFoundError.

If you find yourself facing similar issues, remember: Always check the version of your libraries. Downgrading can often be the key to solving compatibility issues.

By following the steps outlined in this guide, you can successfully create executable files from your Python scripts without running into module-related errors. Happy coding!