TOML Bare Key Regex for Python

What this pattern does

This page provides a lightweight, single-purpose regular expression for matching toml bare key, 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

# TOML Bare Key
# ReDoS-safe | RegexVault — Dev & Systems > Config

import re

toml_bare_key_pattern = re.compile(r'^[a-zA-Z0-9_\-]+$')

def validate_toml_bare_key(value: str) -> bool:
    return bool(toml_bare_key_pattern.fullmatch(value))

# Example
print(validate_toml_bare_key("name"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > Config 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

TOML bare keys are restrictive — dots, spaces, and most special characters require quoting. Dotted keys (table.key = value) are parsed differently — split by dots first. Quoted keys in TOML are valid for names with spaces.