Unix Absolute Path Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching unix absolute path, 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

# Unix Absolute Path
# ReDoS-safe | RegexVault — Dev & Systems > File Paths

import re

unix_absolute_path_pattern = re.compile(r'^\/(?!.*\.\.\/)(?!.*\s)(?!.*\n)(?:[^\/\0]+\/?)*$')

def validate_unix_absolute_path(value: str) -> bool:
    return bool(unix_absolute_path_pattern.fullmatch(value))

# Example
print(validate_unix_absolute_path("/"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > File Paths 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

Intentionally restrictive: no spaces, control characters, or path traversal sequences. Use for validated inputs, not for parsing arbitrary filesystem paths which can contain almost any character except NUL.