Git Commit Hash (Full SHA-1) Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching git commit hash (full sha-1), ported and verified for Python. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# Git Commit Hash (Full SHA-1)
# ReDoS-safe | RegexVault — Dev & Systems > Git

import re

git_commit_hash_full_sha1_pattern = re.compile(r'^[0-9a-fA-F]{40}$')

def validate_git_commit_hash_full_sha1(value: str) -> bool:
    return bool(git_commit_hash_full_sha1_pattern.fullmatch(value))

# Example
print(validate_git_commit_hash_full_sha1("a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > Git category and carries a ReDoS-safe certification. That matters for Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

Git is transitioning from SHA-1 to SHA-256. SHA-256 hashes are 64 hex chars (dev-git-02). The all-zeros hash represents the null tree object.