Outdated or unused code left as comments in Python files can clutter codebases, making them harder to read and maintain.

Eradicate solves this by automatically identifying and removing commented-out code from Python files.

Let’s see eradicate in action:

Example Python file:

# from math import *

def mean(nums: list):
    # print(nums)
    # TODO: check if nums is empty
    # Return mean
    return sum(nums) / len(nums)

# nums = [0, 1]
nums = [1, 2, 3]
mean(nums)

Preview changes:

$ eradicate main.py

--- before/main.py
+++ after/main.py
@@ -1,11 +1,8 @@
-# from math import *

 def mean(nums: list):
-    # print(nums)
     # TODO: check if nums is empty
     # Return mean
     return sum(nums) / len(nums)

-# nums = [0, 1]
 nums = [1, 2, 3]
 mean(nums)

Apply changes:

$ eradicate main.py -i

Results:

def mean(nums: list):
    # TODO: check if nums is empty
    # Return mean
    return sum(nums) / len(nums)

nums = [1, 2, 3]
mean(nums)

In this example, eradicate removes:

1. The commented-out import statement # from math import *
2. The commented-out debug print statement # print(nums)
3. The commented-out variable assignment # nums = [0, 1]

However, it preserves the meaningful comments:

1. The TODO comment # TODO: check if nums is empty
2. The descriptive comment # Return mean

This cleanup improves the code’s readability by removing distracting, unused code comments while keeping important notes for developers.

You can use eradicate with pre-commit by adding the following to your .pre-commit-config.yaml file:

repos:
- repo: https://github.com/wemake-services/eradicate/
  rev: v2.2.0
  hooks:
  - id: eradicate

Link to eradicate.