Python Stack Trace Frame Regex for Python

What this pattern does

This page provides a well-structured, multi-part regular expression for matching python stack trace frame, 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

# Python Stack Trace Frame
# ReDoS-safe | RegexVault — Dev & Systems > Log Parsing

import re

python_stack_trace_frame_pattern = re.compile(r'^\s*File "[^"]+", line [0-9]+, in [^\s]+$')

def validate_python_stack_trace_frame(value: str) -> bool:
    return bool(python_stack_trace_frame_pattern.fullmatch(value))

# Example
print(validate_python_stack_trace_frame("  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 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

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.