Duration / Time Elapsed Extraction Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching duration / time elapsed extraction, 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

# Duration / Time Elapsed Extraction
# ReDoS-safe | RegexVault — Dev & Systems > Log Parsing

import re

duration_time_elapsed_extraction_pattern = re.compile(r'([0-9]+(?:\.[0-9]+)?)\s*(ns|us|ms|s|m|h|min|sec|milliseconds?|microseconds?|seconds?|minutes?|hours?)\b')

def validate_duration_time_elapsed_extraction(value: str) -> bool:
    return bool(duration_time_elapsed_extraction_pattern.fullmatch(value))

# Example
print(validate_duration_time_elapsed_extraction("completed in 125ms"))  # 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=numeric value, 2=unit. Covers nanoseconds to hours. The \b prevents partial unit matches. Parse to a canonical duration type after extraction for comparison and aggregation.