How to Mock Git Clean Dry Run in Python

Simulate the output of `git clean -n` in Python to preview which untracked files would be removed without actually deleting them.

Easy Python 3.9+ Aug 9, 2026 Git + Python 14 views 0 copies

git clean dry-run subprocess simulation

Python code

19 lines

Python 3.9+

import subprocess
import sys

def mock_git_clean_dry_run(untracked_files):
    """Simulate `git clean -n` for a given list of untracked files."""
    if not untracked_files:
        print("No untracked files to remove.")
        return

    print("Would remove:")
    for file in untracked_files:
        print(f"  {file}")

    # Simulate the command output for educational purposes
    print("\n[DRY RUN] No files were actually deleted.")

if __name__ == "__main__":
    files = ["temp.log", "cache/", "notes.txt~"]
    mock_git_clean_dry_run(files)

Output

stdout

Would remove:
  temp.log
  cache/
  notes.txt~

[DRY RUN] No files were actually deleted.

How it works

This function mimics the behavior of git clean -n by printing each untracked file that would be removed. It uses a simple loop to iterate over the list of files and prints them with indentation, similar to real Git output. The dry-run message clarifies that nothing has been deleted, reinforcing the safety of the operation. The if __name__ == '__main__' guard allows the function to be imported and reused elsewhere without executing the demo.

Common mistakes

Forgetting to add a trailing slash to directory names in the output, unlike Git's actual display.
Not handling an empty file list, which would otherwise produce confusing output.
Actually calling `git clean` without `-n` in a real script, which could delete files permanently.

Variations

Use `subprocess.run(["git", "clean", "-n"])` to execute the real command and capture its output.
Return a list of file names instead of printing, to allow programmatic use.

Real-world use cases

In a CI pipeline, you can run a dry run to list files that will be cleaned before a build, preventing accidental deletion of needed assets.
A developer tool that previews which temporary or cache files would be removed by a cleanup script, safely showing the user what would happen.
A testing mock for a function that wraps `git clean -n`, allowing you to verify the logic without touching the real repository.

How to Mock Git Clean Dry Run in Python

Python code

Output

How it works

Common mistakes

Variations

Real-world use cases

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Python code

Output

How it works

Common mistakes

Variations

Real-world use cases

More from Git + Python

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