Automation & scripting
CLI tools, scheduled jobs, filesystem tasks, and glue scripts that save time.
Aggregate Log Errors Count by Hour in Python
Counts ERROR log lines per hour using regex and Counter, returning a sorted dictionary of hourly totals.
import re
from collections import Counter
from datetime import datetime
def aggregate_errors_by_hour(log_lines):
pattern = re.compile(r'^(\d{4}-\d{2}-\d{2} \d{2}):\d{2}:\d{2}.*ERROR')
hourly_counts = Counter()
for line in log_lines:
match = pattern.match(line)
if match:
ho…Build a Live Countdown Timer for Events in Python
A Python script that displays a real-time countdown to a target date and time, updating every second in the console.
import datetime
import time
def countdown(event_name, target_datetime):
"""Displays a live countdown to a target datetime."""
while True:
now = datetime.datetime.now()
remaining = target_datetime - now
if remaining.total_seconds() <= 0:
print(f"\n🚀 {event_name} is happening…Build an RSS feed from markdown blog posts in Python
Scans a folder of markdown files, extracts titles, dates, and excerpts, and generates a valid RSS 2.0 XML feed.
import re
from pathlib import Path
from xml.etree.ElementTree import Element, SubElement, tostring
from datetime import datetime, timezone
from xml.dom import minidom
def build_rss(blog_dir, site_url="https://example.com"):
feed = Element("rss", version="2.0")
channel = SubElement(feed, "channel")
SubElem…Find Best Meeting Time Across Time Zones in Python
This code calculates overlapping available hours among participants in different time zones and returns the best meeting time in UTC and each participant's local time.
from datetime import datetime, timedelta, timezone
from zoneinfo import ZoneInfo
from dataclasses import dataclass
from typing import List, Tuple, Optional
@dataclass
class Participant:
name: str
timezone: str
# weekdays availability: 0=Mon, start_hour (0-23), end_hour (0-23)
available_slots: List[Tup…Generate Holiday Calendars for Different Countries in Python
Generate a sorted list of public holidays for a given country and year using Python's calendar and datetime modules.
import calendar
from datetime import date, timedelta
def generate_holiday_calendar(country_code, year=2025):
holidays = []
if country_code == "US":
# New Year's Day
holidays.append(date(year, 1, 1))
# Independence Day
holidays.append(date(year, 7, 4))
# Thanksgivin…Generate a Monthly Report CSV from Log Files in Python
Reads a CSV log file, filters events by a given month, aggregates daily event counts and revenue, and writes a summarized monthly report to a new CSV.
import csv
from collections import defaultdict
from datetime import datetime
def generate_monthly_report(log_file: str, month: str, output_file: str) -> None:
events_by_date = defaultdict(int)
revenue_by_date = defaultdict(float)
with open(log_file, 'r') as f:
for line in f:
date_…How to Backup an SQLite Database with a Timestamp in Python
Backs up an SQLite database file to a timestamped copy using the sqlite3 backup API.
import sqlite3
import shutil
from datetime import datetime
from pathlib import Path
def backup_database(db_path: str, backup_dir: str = "backups") -> Path:
db = Path(db_path)
backup_folder = Path(backup_dir)
backup_folder.mkdir(exist_ok=True)
timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
…How to Build a Mock Route53 DNS API in Python
Create a mock DNS API server in Python that simulates Route53 record lookups and updates using the standard library.
import json
from http.server import BaseHTTPRequestHandler, HTTPServer
from urllib.parse import urlparse, parse_qs
class DNSUpdateHandler(BaseHTTPRequestHandler):
records = {"example.com": "1.2.3.4"}
def do_GET(self):
domain = parse_qs(urlparse(self.path).query).get("domain", [""])[0]
if dom…How to Bump Version in pyproject.toml Using Regex in Python
Updates the version field in a pyproject.toml file using a regex substitution with the Python standard library.
import re
from pathlib import Path
def bump_version(pyproject_path: str, new_version: str) -> None:
"""Update version in pyproject.toml using regex."""
path = Path(pyproject_path)
content = path.read_text()
# Match version = "x.y.z" (simple or PEP 440 with pre-release)
pattern = r'^version\s*=\s*…How to Check SSL Certificate Expiry in Python
Connect to a host over TLS, extract the certificate's expiry date, and report days remaining using only the Python standard library.
import socket
import ssl
from datetime import datetime
def check_cert_expiry(hostname, port=443):
context = ssl.create_default_context()
with socket.create_connection((hostname, port), timeout=10) as sock:
with context.wrap_socket(sock, server_hostname=hostname) as tls_sock:
cert = tls_soc…How to Filter Docker Containers for Pruning in Python
Simulate Docker's container prune by filtering a JSON list for exited containers older than a cutoff, returning pruned IDs and space freed.
import json
from datetime import datetime, timedelta
def parse_docker_ps(json_output: str, older_than_hours: int = 24) -> list:
containers = json.loads(json_output)
cutoff = datetime.now() - timedelta(hours=older_than_hours)
return [
c for c in containers
if datetime.fromisoformat(c["crea…How to Find Stale GitHub Issues in Python
Filter a list of GitHub issues to find those not updated within a configurable number of days using Python datetime arithmetic.
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…How to Monitor Domain Expiration Dates in Python
A Python script that checks domain expiration dates using the python-whois library and warns when a domain is expiring soon.
import whois
from datetime import datetime, timedelta
import time
def check_domain_expiry(domain_name):
"""Check when a domain expires and warn if soon."""
try:
w = whois.whois(domain_name)
expiry = w.expiration_date
# Handle list or single date
if isinstance(expiry, list):
…How to Update a Hosts File to Block Distractions in Python
This script updates a local hosts file (or a demo file) by adding or updating entries to block distracting websites like Facebook and Twitter.
from pathlib import Path
def update_hosts(entries):
"""
Add or update blocking entries in the hosts file.
Uses a local demo file by default to avoid system changes.
"""
hosts_path = Path("demo_hosts.txt")
# Create demo file if it doesn't exist
if not hosts_path.exists():
hosts…How to Validate SSL Certificates for Multiple Domains in Python
A Python utility that checks SSL certificate expiry dates for a list of domains using the standard library ssl and socket modules.
import ssl
import socket
from datetime import datetime
def check_ssl_certificate(hostname: str, port: int = 443) -> dict:
"""Validate SSL certificate for a given hostname."""
context = ssl.create_default_context()
with socket.create_connection((hostname, port), timeout=5) as sock:
with context.wra…How to Write an IP Block List to hosts.deny in Python
This Python script validates a list of IP addresses and CIDR ranges, then writes them to a hosts.deny file to block connections at the TCP wrapper level.
from ipaddress import ip_network
def write_hosts_deny(ip_list, output_file="hosts.deny"):
with open(output_file, "w") as f:
for ip in ip_list:
try:
ip_network(ip)
f.write(f"ALL: {ip}\n")
except ValueError:
continue
print(f"Written…How to validate argparse CLI commands in Python
Build a beginner-friendly command-line argument parser with argparse, including required and optional arguments, plus simple validation for age.
import argparse
def main():
parser = argparse.ArgumentParser(description="Validate CLI arguments for beginners.")
parser.add_argument("name", type=str, help="Your name.")
parser.add_argument("--age", type=int, default=None, help="Your age (optional).")
parser.add_argument("--verbose", action="store_t…Parse WHOIS Data with Python Regex
Extract domain registration fields from a mock WHOIS record using regex and compute days until expiration.
import re
from datetime import datetime
def parse_whois(whois_text: str) -> dict:
"""Extract key registration fields from a mock WHOIS record."""
patterns = {
"domain": r"Domain Name:\s*(.+)",
"registrar": r"Registrar:\s*(.+)",
"creation_date": r"Creation Date:\s*(.+)",
"expir…Parse cron expression and compute next run datetime in Python
Parse a 5-field cron expression and compute the next matching datetime starting from a given base time.
from datetime import datetime, timedelta
import re
def parse_cron_and_next_run(cron_expr, base_time=None):
"""Parse a cron expression and compute the next run time."""
if base_time is None:
base_time = datetime.now().replace(second=0, microsecond=0)
fields = cron_expr.split()
if len(fields) !…Resize Disk Partitions in Python (Mock Script)
A mock disk partition resize script that uses dataclasses to model partitions, validate new sizes, and output the updated layout as JSON.
#!/usr/bin/env python3
"""Mock script to demonstrate disk partition resize logic."""
import json
from dataclasses import dataclass
from typing import Dict
@dataclass
class Partition:
name: str
size_gb: int
mount_point: str
def to_dict(self) -> Dict[str, object]:
return {
"name": …Restrict Secrets File Permissions with the chmod Script in Python
This script restricts a secrets file to 0600 permissions, rotates it to a dated backup, and creates a fresh protected file for secure automation workflows.
import os
import sys
import stat
from pathlib import Path
def restrict_secrets_file(filepath: str) -> None:
"""Set restrictive permissions (0600) on a secrets file."""
path = Path(filepath).expanduser()
if not path.is_file():
raise FileNotFoundError(f"Secrets file not found: {path}")
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