ISO 4217 Currency Code Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching iso 4217 currency code, ported and verified for Python. Financial data validation has zero tolerance for false negatives — a missed invalid entry can corrupt downstream calculations. 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

# ISO 4217 Currency Code
# ReDoS-safe | RegexVault — Finance > Currency & Money

import re

iso_4217_currency_code_pattern = re.compile(r'^[A-Z]{3}$')

def validate_iso_4217_currency_code(value: str) -> bool:
    return bool(iso_4217_currency_code_pattern.fullmatch(value))

# Example
print(validate_iso_4217_currency_code("USD"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Currency & Money 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

ISO 4217 codes are always 3 uppercase letters. Cryptocurrency codes (BTC, ETH) are not part of the ISO standard but some systems treat them as currency codes. X-prefixed codes are special (XAU=gold, XDR=SDR).