Clean Up Your Python Code with PySCN: Find Clones and Dead Code

Ever opened a large, old Python codebase and felt a slight sense of dread? You know there's probably duplicated logic scattered across modules and functions that haven't been called in years, but finding it manually is a slog. That's where automated tools come in, and PySCN is a new one that's worth a look.

It's a static analysis tool built specifically for Python that scans your entire repository to pinpoint two common sources of technical debt: code clones and dead functions. It gives you a concrete report, so you can start refactoring or cleaning with confidence, not guesswork.

What It Does

In short, PySCN analyzes your Python project's abstract syntax trees (ASTs). It doesn't run your code; it reads it, much like a linter. By doing this, it can:

1. Detect Code Clones: It finds sequences of code that are structurally similar or identical across different files. This isn't just about exact string matches—it can find clones where variable names have been changed.
2. Identify Dead Functions: It looks for functions (and methods) that are defined but never called anywhere within the codebase. These are prime candidates for removal.

The output is a straightforward list or visualization of the issues it finds, giving you a clear starting point for cleanup.

Why It's Cool

While there are other tools that do similar things, PySCN stands out for being purpose-built and straightforward for Python. It's not buried inside a massive, multi-language suite. You run it, it gives you a report about your project. The value is immediate.

For developers inheriting a legacy project or for teams wanting to keep their growing codebase healthy, this kind of automated audit is incredibly useful. It turns a vague "we should reduce duplication" into a task list: "Here are the 12 functions with significant overlap between services/auth.py and legacy/user_handlers.py."

Finding dead code is especially powerful for reducing maintenance burden and cognitive load. There's no reason to keep, test, or think about a function that nothing uses.

How to Try It

Getting started is simple. PySCN is on GitHub and installable via pip.

First, install it:

pip install pyscn

Then, navigate to your project's root directory and run the scan:

pyscn scan /path/to/your/project

You can customize the output format and adjust sensitivity for clone detection. Check out the PySCN GitHub repository for all the options and examples