CFI Code (Classification of Financial Instruments) Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching cfi code (classification of financial instruments), 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

# CFI Code (Classification of Financial Instruments)
# ReDoS-safe | RegexVault — Finance > Securities & Trading

import re

cfi_code_classification_of_financial_instruments_pattern = re.compile(r'^[A-Z]{6}$')

def validate_cfi_code_classification_of_financial_instruments(value: str) -> bool:
    return bool(cfi_code_classification_of_financial_instruments_pattern.fullmatch(value))

# Example
print(validate_cfi_code_classification_of_financial_instruments("ESXXXX"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Finance > Securities & Trading 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

CFI codes classify financial instruments. First char: E=equity, D=debt, R=rights, O=option, F=futures, C=collective investment, P=structured, T=referential. X means 'not applicable/defined'. Used in ANNA (ISIN authority) systems.