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Track Internet Connectivity and Downtime Automatically in Python
Monitors internet connectivity by pinging a remote host and logs any downtime events with timestamps and duration.
import time
import subprocess
from datetime import datetime
def check_internet(host="8.8.8.8", timeout=3):
"""Returns True if internet is reachable via ping."""
try:
subprocess.run(
["ping", "-c", "1", "-W", str(timeout), host],
capture_output=True,
timeout=timeout …Build a Python Utility That Detects Duplicate Records Across Multiple Excel Sheets
A Python utility that uses pandas to find overlapping records across different Excel sheets based on specified key columns.
import pandas as pd
from pathlib import Path
def find_duplicate_records_across_sheets(file_path: str, key_columns: list, sheet_names: list) -> dict:
"""
Detect duplicate records across multiple Excel sheets based on specified key columns.
Args:
file_path: Path to the Excel file
key_co…Check Null Rate Threshold in PySpark DataFrame
This PySpark code checks the null rate of specified DataFrame columns against a threshold and returns violations.
from pyspark.sql import SparkSession
from pyspark.sql.functions import col, sum, count
def check_null_rate(df, threshold=0.2, columns=None):
"""
Check null rate for specified columns (or all) against a threshold.
Returns columns that exceed the threshold.
"""
cols = columns or df.columns
total…Deduplicate events by ID within a window in Python
Deduplicate event streams by ID within sliding time windows, keeping the newest occurrence per window using heaps and sets.
import heapq
from collections import defaultdict
def deduplicate_events(events, window_size):
"""Return events deduplicated by id, keeping newest within each sliding window."""
# Index events by (timestamp, id) for deterministic ordering
events_by_id = defaultdict(list)
for ts, eid, *payload in events…Enrich a stream with reference data by key lookup in Python
Uses streamz to join each incoming record to a reference dictionary by name, adding department and level fields or defaults.
from streamz import Stream
reference = {"alice": {"dept": "eng", "level": 3}, "bob": {"dept": "sales", "level": 5}}
def enrich(record):
name = record.get("name")
ref = reference.get(name)
joined = dict(record)
if ref:
joined.update(ref)
else:
joined["dept"] = "unknown"
joi…Extract Schema.org Structured Data from Any Website in Python
A Python tool that fetches a webpage and extracts all JSON-LD structured data (Schema.org) embedded in <script> tags with type="application/ld+json".
import requests
from bs4 import BeautifulSoup
import json
def extract_schema_org(url):
"""Extract structured data (Schema.org) from a website."""
try:
response = requests.get(url, timeout=10)
response.raise_for_status()
except requests.exceptions.RequestException as e:
return {"err…How to Count Events by Minute with a Tumbling Window in Python
Group timestamps into fixed 60-second tumbling windows and count events per bucket using a dict.
from collections import defaultdict
from datetime import datetime, timedelta
def tumbling_window_count(events, window_seconds=60):
buckets = defaultdict(int)
for event in events:
ts = datetime.fromisoformat(event["timestamp"])
bucket_start = ts - timedelta(seconds=ts.second % window_seconds,
…How to Implement SCD Type 1 Overwrite in Python with SQLite
Implement SCD Type 1 dimension updates in Python using SQLite — overwrite existing rows with new data while preserving keys.
import sqlite3
# Simulate a dimension table with SCD Type 1 (overwrite)
conn = sqlite3.connect(":memory:")
cursor = conn.cursor()
# Create dimension table
cursor.execute("""
CREATE TABLE customer_dim (
customer_id INTEGER PRIMARY KEY,
customer_name TEXT,
city TEXT,
updated_at TEXT…How to Implement Slowly Changing Dimension Type 2 History in Python
Build a type-2 slowly changing dimension pipeline that closes old records and opens new ones when customer data changes.
from datetime import datetime, timedelta
def apply_scd_type2(records, current_date):
"""Returns active records after inserting new records with type-2 history."""
history = []
active = {}
for record in records:
key = record["customer_id"]
if key in active:
active[key]["end…How to Stream a Large JSONL File Line by Line in Python
Process a large JSON-lines file incrementally using streaming techniques to avoid loading the entire file into memory.
import json
def process_large_file(filepath, chunk_size=8192):
"""
Stream a large JSON-lines file line by line, processing each record
without loading the entire file into memory.
"""
total_count = 0
total_sum = 0
with open(filepath, 'r') as f:
while True:
chunk = …How to Validate Fact Table Grain Row Counts in Python
Validate fact table grain by checking dimension key references, unique grain combinations, duplicate rows, and dimension cardinality from a CSV file.
import csv
import hashlib
from pathlib import Path
def validate_fact_grain(fact_file: Path, expected_dim_keys: dict[str, set[str]]) -> dict:
"""
Validate fact table grain by checking each row's dimension keys exist
in expected dimension tables and row count consistency.
"""
dim_references = {}
…Implement an Out-of-Order Sort Buffer with a Heap in Python
Buffers out-of-order indices from a stream and emits them in sorted order using a min-heap with a sliding window.
import heapq
from collections import deque
class OutOfOrderSorter:
def __init__(self, buffer_size):
self.buffer_size = buffer_size
self.buffer = deque(maxlen=buffer_size)
self.heap = []
self.next_expected_index = 0
self.result = []
def push(self, item):
heapq.…Map Partition Over Chunks in Python with Multiprocessing and Mock
Process data in chunks across multiple CPU cores using multiprocessing Pool.map, and mock the chunk function to test partitioning behavior without heavy computation.
from multiprocessing import Pool
from unittest.mock import patch, Mock
def process_chunk(chunk):
return [x * x for x in chunk]
def map_partition_over_chunks(data, chunk_size, process_func=process_chunk):
chunks = [data[i:i + chunk_size] for i in range(0, len(data), chunk_size)]
with Pool() as pool:
…Normalize Timestamps to UTC DateTime in Python
Convert timestamps in multiple formats to UTC-aware datetime objects using datetime.strptime and astimezone.
from datetime import datetime, timezone
raw_timestamps = [
"2024-01-15 14:30:00+02:00",
"17/05/2024 09:15:00 -0500",
"2024-03-01T22:45:00Z",
"2024-06-20 08:00:00+09:30"
]
def parse_and_convert(ts: str) -> datetime:
normalized_ts = ts.strip().replace("Z", "+00:00")
formats = [
"%Y-%m-%…Pivot long to wide transformation dict
Transform a list of dictionaries from long format to wide format by pivoting on a key column and aggregating values, using pure Python.
def pivot_long_to_wide(rows, key_col, value_col, id_cols=None):
"""
Convert long-format data (list of dicts) to wide format.
Args:
rows: List of dicts in long format
key_col: Column name to pivot on (becomes new column headers)
value_col: Column name whose values become the cel…Python Exponential Backoff Retry Example
Retry a flaky function with exponential backoff and jitter-free delays, printing each attempt and finally returning the successful result.
import random
import time
def flaky_function():
if random.random() < 0.6:
raise ConnectionError("Temporary network error")
return "success"
def retry_with_exponential_backoff(func, max_retries=5, base_delay=1.0):
for attempt in range(max_retries + 1):
try:
return func()
…Find the Commit That Introduced a String in Git History Using Python
Use git log -S with Python subprocess to find the earliest commit that introduced a specific string across your repository history.
import subprocess
import sys
def find_introducing_commit(repo_path: str, search_string: str, file_glob: str = "*") -> str:
"""Find the first commit that introduced a given string in a git repository."""
result = subprocess.run(
["git", "-C", repo_path, "log", "--all", "--oneline", "-S", search_string…Generate CHANGELOG from Conventional Commits in Python
Parse your git log for conventional commits (feat, fix) and produce a simple Markdown CHANGELOG with grouped features and bug fixes.
import subprocess
import re
import sys
from collections import OrderedDict
CONVENTIONAL_COMMIT = re.compile(
r"^(?P<type>feat|fix|chore|docs|refactor|perf|test|build|ci|style)(?:\((?P<scope>[^)]+)\))?: (?P<description>.+)"
)
def get_git_log():
return subprocess.run(
["git", "log", "--format=%s"],
…Generate Release Notes Markdown from PR Titles in Python
Generate structured Markdown release notes from a list of pull request titles using conventional commit types.
import json
from datetime import datetime, timezone
PRS = [
{"title": "feat: add user login", "number": 12, "merged_at": "2025-01-10"},
{"title": "fix: resolve payment timeout", "number": 13, "merged_at": "2025-01-11"},
{"title": "chore: bump dependencies", "number": 14, "merged_at": "2025-01-12"},
{"…How to Archive a Repository as a ZIP in Python
Create a ZIP archive of a repository directory with a mock export, skipping hidden files and __pycache__ folders.
import zipfile
import io
import os
from pathlib import Path
def archive_repo_mock(repo_path, output_path="repo_archive.zip"):
"""Create a zip archive of a repository directory (mock export)."""
repo = Path(repo_path)
if not repo.exists():
raise FileNotFoundError(f"Repository not found: {repo}")
…How to Build a Branch Protection Audit Mock API in Python
A mock HTTP API that serves branch protection rules for repositories and audits them for compliance, built with Python's standard library.
import json
from http.server import BaseHTTPRequestHandler, HTTPServer
from urllib.parse import urlparse, parse_qs
REPOSITORIES = {
"alpha": {
"default_branch": "main",
"branches": ["main", "develop", "feature-x"],
"protection_rules": {
"main": {"required_reviews": 2, "dismiss_…How to Format Git Patch Series as an MBOX File in Python
Generate a patch-series mbox file from commit metadata with numbered [PATCH nnn/nnn] subjects and a Git-style footer.
import re
from pathlib import Path
def format_patch_series_mbox(commits, output_path="series.mbox"):
entries = []
for idx, commit in enumerate(commits, start=1):
subject = commit["subject"]
author = commit["author"]
email = commit["email"]
date = commit["date"]
body = …How to Generate Release Notes from Git Commit Messages in Python
This script fetches recent Git commit messages using conventional commit prefixes (feat, fix, etc.), categorizes them, and prints formatted release notes with today's date.
import subprocess
import re
from datetime import datetime
def get_git_log(since_tag="HEAD~10", format_str="%s"):
"""Retrieve commit messages from git log."""
try:
result = subprocess.run(
["git", "log", f"--since={since_tag}", f"--format={format_str}"],
capture_output=True,
…How to Get Current Git Branch Name in Python with Mock Subprocess
Mocks the subprocess call to reliably test the current git branch name retrieval using GitPython.
import subprocess
from unittest.mock import patch, MagicMock
from git import Repo
import os
def get_current_branch(repo_path="."):
"""Get the current branch name of a git repository."""
repo = Repo(repo_path)
return repo.active_branch.name
if __name__ == "__main__":
# Mock subprocess to control the…Browse by section
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