Is it safe to use on production code?

Yes, the tool is designed to prioritize safe transformations and will skip complex cases that might alter behavior, though running your test suite after conversion is always recommended.

Does this tool support large directories?

Yes, the skill can recursively process entire project directories to modernize all Python files in a single pass.

Can it handle string concatenation?

Yes, by enabling the specific transformation flags, the tool can convert manual string addition (+) into cleaner, more modern f-strings.

Can I use this in my CI/CD pipeline?

Yes, the skill supports a 'fail-on-change' flag which is ideal for automated checks to ensure no legacy string formatting is introduced into your repository.

Can I preview changes before they are applied?

Absolutely. You can use the dry-run command to see exactly which lines will be modified without making any changes to your source files.

Python F-String Modernizer

Name: Python F-String Modernizer
Author: FlexNetOS

byFlexNetOS

0•

Developer Tools

Automates the modernization of legacy Python codebases by converting old-style string formatting to efficient, readable f-strings.

The Python F-String Modernizer leverages the powerful flynt utility to automatically refactor legacy string formatting—including %-style and .format() calls—into modern Python f-strings. This skill simplifies codebase maintenance by recursively processing entire directories, handling complex string concatenations, and ensuring safe transformations that preserve logic while improving both readability and execution speed. It is an essential tool for developers aiming to upgrade legacy Python projects to modern standards (Python 3.6+) with minimal manual intervention.

Key Features

010 GitHub stars

02Recursive directory processing for efficient batch modernization of large projects

03Granular control with dry-run modes, line length limits, and CI/CD integration options

04Automated conversion of legacy %-formatting and .format() calls to modern f-strings

05Safe transformation logic that skips complex expressions to prevent logical regressions

06Support for transforming string concatenations and static joins into clean f-strings

Use Cases

01Modernizing legacy Python 2 or early Python 3 codebases to adopt 3.6+ best practices

02Automating string formatting standardization within continuous integration pipelines

03Improving code readability and runtime performance across large-scale software projects

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add flexnetos/ripple-env python-flynt-tool

For use in Claude.ai and ChatGPT

Download Skill