Python Stack Trace Frame Regex for JavaScript

What this pattern does

This page provides a well-structured, multi-part regular expression for matching python stack trace frame, ported and verified for JavaScript. A rigorously tested regex reduces debugging time and protects your application from edge-case failures. The snippet below is ready to drop into your JavaScript project — whether you're validating in an Express middleware, a Next.js API route, or a client-side form.

Javascript Implementation

// Python Stack Trace Frame
// ReDoS-checked | RegexVault — Dev & Systems > Log Parsing

const pythonStackTraceFrameRegex = /^\s*File "[^"]+", line [0-9]+, in [^\s]+$/;

function validatePythonStackTraceFrame(input: string): boolean {
  return pythonStackTraceFrameRegex.test(input);
}

// Example
console.log(validatePythonStackTraceFrame("  File "/app/main.py", line 42, in main")); // true

Test Cases

When to use this pattern

This pattern is drawn from the Dev & Systems > Log Parsing category and has been checked for ReDoS risk. That matters for JavaScript developers because especially critical in long-running Node.js event loops where a ReDoS vulnerability can block the entire process. 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

Groups: 1=file path (can be <stdin> or <string>), 2=line number, 3=function name (<module> for top-level code). The < > characters in group 3 handle <module>, <listcomp>, etc.