Migrating from typed_ast to the native ast module in Python 3.8 and newer

Migrating from typed_ast to the native ast module in Python 3.8 and newer

With the release of Python 3.8, the native ast module has been augmented to support the extraction of type comments and has limited support for parsing older versions of Python 3. This enhancement makes it recommended to transition from using the typed_ast package to the native ast module for parsing and manipulating abstract syntax trees (ASTs) in Python code.

The typed_ast package, which provides a Python 2.7 and Python 3 parser similar to the standard ast library, is no longer maintained as of the time of writing this article. Instead, the standard library ast module should be used for new projects or when upgrading to Python 3.8 and newer versions.

The benefits of migrating to the native ast module include improved compatibility with the Python ecosystem, better support from the Python core development team, and the removal of potential future compatibility issues with the typed_ast package.

To migrate your code from typed_ast to the native ast module, follow these steps:

1. Update your code to import the ast module from the standard library instead of the typed_ast package.

2. Review your codebase for any specific features or functionality that relied on the additional fields or optional arguments provided by the typed_ast package. Adjust your code to work with the standard ast module by using alternative approaches or rethinking the design where necessary.

3. Update any code that integrates with the typed_ast package, such as code generators or analyzers, to use the native ast module instead. Ensure that the functionality is preserved after the migration.

4. Test your code thoroughly to ensure that it behaves as expected with the new ast module. Pay attention to any differences in behavior or output compared to the typed_ast package.

5. Update your development environment to use Python 3.8 or newer if you haven’t already. Install any necessary dependencies related to the ast module or make sure they are compatible with the new version of Python.

By migrating to the native ast module, you can future-proof your code by aligning with the standard library and leveraging the ongoing improvements and support from the Python community. The transition may require some adjustments, but the benefits of using the native ast module outweigh the potential challenges.

Remember to consult the official Python documentation for detailed information on using the ast module and any specific changes introduced in Python 3.8 and subsequent versions.

If you have any questions or need further assistance with the migration process, don’t hesitate to reach out to the Python community through forums, mailing lists, or online communities.

Happy coding!

References

• typed_ast GitHub repository: https://github.com/python/typed_ast
• ast module in Python documentation: https://docs.python.org/3/library/ast.html
• Python Developer’s Guide: https://devguide.python.org/