PCI-DSS Requirement Reference Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching pci-dss requirement reference, ported and verified for Python. In security-sensitive code, using an unverified regex can open the door to both false positives and denial-of-service attacks. 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

# PCI-DSS Requirement Reference
# ReDoS-safe | RegexVault — Security > Audit & Compliance

import re

pcidss_requirement_reference_pattern = re.compile(r'^Req(?:uirement)?\s*([1-9]|1[0-2])(?:\.([1-9]|[1-9][0-9])(?:\.([1-9]|[1-9][0-9]))?)?$')

def validate_pcidss_requirement_reference(value: str) -> bool:
    return bool(pcidss_requirement_reference_pattern.fullmatch(value))

# Example
print(validate_pcidss_requirement_reference("Requirement 3"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Security > Audit & Compliance 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

PCI-DSS v4.0 (released March 2022, mandatory from March 2025) has 12 requirements. Key requirements: 3 (Protect stored cardholder data), 4 (Encrypt transmission), 6 (Develop/maintain secure systems), 10 (Log and monitor), 12 (Information security policy). v4.0 adds 64 new requirements vs v3.2.1.