FTP URL Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching ftp url, 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

# FTP URL
# ReDoS-safe | RegexVault — Web & Network > URL

import re

ftp_url_pattern = re.compile(r'^ftps?://(?:[a-zA-Z0-9._~!$&'()*+,;=%-]+(?::[a-zA-Z0-9._~!$&'()*+,;=%-]*)?@)?(?:[a-zA-Z0-9\-]+\.)+[a-zA-Z]{2,63}(?::[1-9][0-9]{0,4})?(?:/[^\s]*)?$')

def validate_ftp_url(value: str) -> bool:
    return bool(ftp_url_pattern.fullmatch(value))

# Example
print(validate_ftp_url("ftp://files.example.com"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Web & Network > URL 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

Credentials in URLs are a security risk — prefer separate authentication mechanisms. FTPS (FTP over SSL) typically uses port 990.