South African Postal Code Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching south african postal code, 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

# South African Postal Code
# ReDoS-safe | RegexVault — Localization > Postal Codes

import re

south_african_postal_code_pattern = re.compile(r'^([0-9]{4})$')

def validate_south_african_postal_code(value: str) -> bool:
    return bool(south_african_postal_code_pattern.fullmatch(value))

# Example
print(validate_south_african_postal_code("0001"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Localization > Postal Codes 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

South African postal codes range from 0001 (Pretoria administrative offices) to 9999. Major cities: Johannesburg 2001, Cape Town 8001, Durban 4001, Pretoria 0002. Leading zeros are significant for some areas.