How to Find Stale GitHub Issues in Python

import os
from datetime import datetime, timezone, timedelta
import re

# Simulated GitHub issue data structure
SAMPLE_ISSUES = [
    {"number": 101, "title": "Login button not working", "updated_at": "2025-06-01T12:00:00Z", "assignee": "alice"},
    {"number": 102, "title": "Fix database migration error", "updated_at": "2025-10-20T08:30:00Z", "assignee": None},
    {"number": 103, "title": "Update API documentation", "updated_at": "2025-10-15T14:15:00Z", "assignee": "bob"},
    {"number": 104, "title": "Refactor authentication module", "updated_at": "2025-09-01T09:00:00Z", "assignee": None},
]

STALE_DAYS = 30  # Consider issues stale if not updated in this many days

def parse_github_date(date_str):
    """Parse GitHub ISO 8601 date string to datetime object."""
    # Remove trailing Z and add UTC timezone
    if date_str.endswith('Z'):
        date_str = date_str[:-1] + '+00:00'
    return datetime.fromisoformat(date_str)

def is_stale(issue, stale_days):
    """Check if an issue is stale based on last update time."""
    last_updated = parse_github_date(issue["updated_at"])
    now = datetime.now(timezone.utc)
    return now - last_updated > timedelta(days=stale_days)

def find_stale_issues(issues, stale_days=STALE_DAYS):
    """Filter list of issues to find only stale ones."""
    stale_issues = []
    for issue in issues:
        if is_stale(issue, stale_days):
            stale_issues.append(issue)
    return stale_issues

if __name__ == "__main__":
    stale_issues = find_stale_issues(SAMPLE_ISSUES)
    
    print(f"Checking for issues stale more than {STALE_DAYS} days...\n")
    
    if not stale_issues:
        print("No stale issues found.")
    else:
        print(f"Found {len(stale_issues)} stale issue(s):\n")
        for issue in stale_issues:
            assignee = issue.get("assignee", "unassigned")
            print(f"  #{issue['number']}: {issue['title']} (last updated: {issue['updated_at']}, assignee: {assignee})")