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Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
How to parallel map embeddings with a thread pool in Python
Run embedding computations in parallel using ThreadPoolExecutor, collect results into a dict keyed by the original item.
import threading
from concurrent.futures import ThreadPoolExecutor
import time
def compute_embedding(item: int) -> tuple[int, int]:
time.sleep(0.05) # Simulate embedding work
return item, item * 10
def parallel_map_embed(items, max_workers=3):
results = {}
with ThreadPoolExecutor(max_workers=max_w…Parse ReAct Logs into Thought Action Observation Steps in Python
Parse a ReAct agent's textual log into structured steps with thought, action, and observation using regex and named tuples.
import re
from collections import namedtuple
ReActStep = namedtuple("ReActStep", ["thought", "action", "observation"])
def parse_react_log(log: str) -> list[ReActStep]:
"""Parse a ReAct log into structured thought/action/observation steps."""
pattern = re.compile(
r"Thought:\s*(?P<thought>.+?)\s*"
…Route Tool Call Name to Python Handler Dict
Routes a tool call name to the correct Python handler function using a dictionary lookup, returning an error for unknown tools.
def get_name():
return {"name": "Alice"}
def get_age():
return {"age": 30}
def get_email():
return {"email": "alice@example.com"}
handlers = {
"get_name": get_name,
"get_age": get_age,
"get_email": get_email,
}
def route(tool_call):
handler = handlers.get(tool_call["name"])
if handl…Serialize and Format Data for LLM Prompts in Python
Use dataclasses and the json module to convert Python objects to JSON strings, parse them back, and format structured data into prompt-friendly text for LLM calls.
import json
from dataclasses import dataclass, asdict
@dataclass
class Recipe:
"""Simple data model to represent a recipe."""
name: str
cuisine: str
prep_minutes: int
def to_json(recipe: Recipe) -> str:
"""Serialize a Recipe to a JSON string."""
return json.dumps(asdict(recipe), indent=2)
…Build a Command-Line Password Generator in Python
Generate cryptographically strong random passwords using Python's secrets module and print them for command-line use.
import secrets
import string
def generate_password(length=16):
"""Generate a cryptographically strong random password."""
alphabet = string.ascii_letters + string.digits + string.punctuation
password = ''.join(secrets.choice(alphabet) for _ in range(length))
return password
if __name__ == "__main__":…Build a Complete Website Sitemap Generator Without External Services
Crawl a website recursively using only Python's standard library to generate a structured sitemap of internal links.
import json
from urllib.parse import urlparse, urljoin
from collections import deque
import urllib.request
import urllib.error
import re
from html.parser import HTMLParser
class SitemapParser(HTMLParser):
def __init__(self, base_url):
super().__init__()
self.base_url = base_url
self.links …Build a Python Tool to Find All API Endpoints on a Website
A Python script that crawls a website, searches for common API endpoint patterns in HTML and JavaScript, and returns all discovered public API URLs.
import re
import requests
from urllib.parse import urljoin, urlparse
from collections import deque
def find_api_endpoints(base_url, max_pages=10):
visited = set()
queue = deque([base_url])
api_endpoints = set()
api_patterns = [
r'/api/[a-zA-Z0-9_/-]+',
r'/v[0-9]+/[a-zA-Z0-9_/-]+',…Build a Python Utility That Verifies Backup Integrity Automatically
Automatically compute and verify SHA-256 checksums of backup files using a JSON manifest to detect missing or corrupted data.
import hashlib
import os
import json
def compute_checksum(filepath, algorithm='sha256'):
"""Compute checksum for the given file."""
hash_func = hashlib.new(algorithm)
with open(filepath, 'rb') as f:
for chunk in iter(lambda: f.read(4096), b''):
hash_func.update(chunk)
return hash_f…Check Service Ping Status and Exit Code in Python
Ping a list of hosts, print OK/FAIL per host, and exit with a non-zero code when any host is unreachable.
import subprocess
import sys
SERVICES = [
"8.8.8.8",
"1.1.1.1",
"invalid-host",
]
def main():
failed = []
for host in SERVICES:
result = subprocess.run(
["ping", "-c", "1", "-W", "2", host],
stdout=subprocess.DEVNULL,
stderr=subprocess.DEVNULL,
…Convert HTML Tables to Excel Reports in Python
Convert HTML tables into formatted Excel reports using BeautifulSoup and Pandas with auto-adjusted column widths.
import pandas as pd
from bs4 import BeautifulSoup
from pathlib import Path
def html_table_to_excel(html_file: str, excel_file: str) -> None:
"""Convert HTML table to formatted Excel report."""
with open(html_file, 'r', encoding='utf-8') as f:
html_content = f.read()
soup = BeautifulSoup(html_…Detect Circular Imports Across Python Projects Automatically
This script walks through all .py files in a directory, builds an import graph, and uses depth-first search to find cycles—printing each circular dependency chain.
import ast
import sys
from pathlib import Path
from collections import defaultdict, deque
def find_imports(filepath):
"""Return set of module names imported by a Python file."""
imports = set()
try:
with open(filepath) as f:
tree = ast.parse(f.read())
except (SyntaxError, UnicodeDe…Fetch weather API mock and write dashboard HTML in Python
This script fetches a mock weather API response as a Python dict, builds a simple HTML dashboard, writes it to a file, and prints both the file path and JSON payload.
from datetime import datetime
import json
import os
def fetch_weather_mock(city: str) -> dict:
"""Return a mock weather payload for a given city."""
return {
"city": city,
"temperature_c": 21.5,
"condition": "Partly Cloudy",
"humidity": 58,
"wind_kph": 12.3,
"u…Find Broken Image References Across a Website in Python
Crawl internal pages of a website, collect all image source URLs, then check each with HEAD requests to report any that return HTTP 4xx or connection errors.
import requests
from urllib.parse import urljoin, urlparse
from bs4 import BeautifulSoup
from concurrent.futures import ThreadPoolExecutor, as_completed
def find_all_links(base_url, max_pages=50):
visited, to_visit = set(), {base_url}
while to_visit and len(visited) < max_pages:
url = to_visit.pop()
…Find the Largest Files Consuming Disk Space with a Beautiful Terminal Report in Python
Scan a directory recursively and print a formatted terminal report of the largest files, with human-readable sizes.
import os
import sys
from pathlib import Path
def get_largest_files(directory: str, count: int = 10) -> list:
"""
Scan the given directory and return the largest files.
Args:
directory: Path to the directory to scan
count: Number of largest files to return
Returns:
…How to Auto Organize Downloads by File Extension in Python
A Python script that sorts files in a directory into subfolders based on their file extensions, creating folders automatically.
import os
import shutil
from pathlib import Path
def organize_downloads(download_dir="~/Downloads"):
"""Move files in a directory into subfolders based on file extension."""
download_path = Path(download_dir).expanduser()
if not download_path.exists():
print(f"Directory not found: {download_p…How to Build a Python argparse CLI for Beginners
Build a beginner-friendly command-line interface using Python's argparse module with positional and optional arguments.
import argparse
def greet(name, greeting="Hello", uppercase=False):
message = f"{greeting}, {name}!"
if uppercase:
message = message.upper()
return message
def main():
parser = argparse.ArgumentParser(description="A simple CLI greet tool for beginners.")
parser.add_argument("name", help="…How to Build a Simple argparse CLI in Python
Create a beginner-friendly command-line tool with argparse that reads a file, optionally uppercases its lines, and prints a configurable number of lines.
import argparse
def main():
parser = argparse.ArgumentParser(
description="Automate file processing with a simple CLI tool."
)
parser.add_argument("filename", help="Path to the input file")
parser.add_argument("--uppercase", action="store_true", help="Convert text to uppercase")
parser.add…How to Build an argparse CLI That Filters File Lines by Keyword in Python
This Python script is a command-line tool built with argparse that reads a text file and prints only the lines that contain (or don't contain) a given keyword.
import argparse
import sys
def main():
parser = argparse.ArgumentParser(description="Filter lines from a file by keyword.")
parser.add_argument("input", type=str, help="File to read")
parser.add_argument("keyword", type=str, help="Keyword to filter lines")
parser.add_argument("--contains", action="sto…How to Build an argparse Command-Line Tool in Python
Create a simple file-info CLI with argparse that counts lines and prints file size, with optional verbose and output flags.
import argparse
import os
from pathlib import Path
def process_file(filepath, verbose=False):
"""Read a file and report its size and line count."""
path = Path(filepath)
if not path.exists():
raise FileNotFoundError(f"File not found: {filepath}")
content = path.read_text()
lines = conten…How to Check Website Status Codes in Python
This script checks the HTTP status codes of multiple URLs concurrently using a thread pool and prints the results.
import requests
from concurrent.futures import ThreadPoolExecutor
URLS = [
"https://www.google.com",
"https://www.python.org",
"https://www.nonexistent-site-12345.com",
"https://www.github.com",
]
def check_status(url):
try:
response = requests.get(url, timeout=5)
return url, resp…How to Compare Two GitHub Repositories and Highlight Differences in Python
Fetch metadata from two GitHub repositories using the GitHub API and compare key attributes like stars, forks, license, and language, printing any differences.
import requests
import json
from pathlib import Path
def fetch_repo_data(owner, repo_name):
"""Fetch repository metadata from GitHub API."""
url = f"https://api.github.com/repos/{owner}/{repo_name}"
response = requests.get(url)
response.raise_for_status()
return response.json()
def compare_repos(…How to Compress a Folder in Python While Preserving Directory Structure
A Python function that uses zipfile to recursively compress a folder, maintaining the original directory hierarchy inside the zip archive.
import os
import zipfile
from pathlib import Path
def compress_folder(source_dir: str, output_zip: str):
"""
Compress a folder into a zip file, preserving the directory structure.
Args:
source_dir: Path to the source directory to compress
output_zip: Path for the output zip file
"…How to Create a File Organizer That Sorts Files Automatically in Python
A Python script that scans a given folder, categorizes files by extension (Images, Documents, Audio, Video, Archives, Misc), and moves them into subfolders automatically.
import os
import shutil
from pathlib import Path
FILE_CATEGORIES = {
"Images": [".jpg", ".jpeg", ".png", ".gif", ".bmp"],
"Documents": [".pdf", ".docx", ".txt", ".csv", ".xlsx"],
"Audio": [".mp3", ".wav", ".flac", ".aac"],
"Video": [".mp4", ".mkv", ".avi", ".mov"],
"Archives": [".zip", ".tar", ".g…How to Create a Link Graph Visualization for Any Website in Python
A Python script that crawls a website's internal links, builds a directed graph of parent-child URL relationships, and prints the graph to the console.
import requests
from bs4 import BeautifulSoup
from collections import defaultdict
from urllib.parse import urljoin, urlparse
import sys
def get_links(url, max_links=20):
try:
response = requests.get(url, timeout=5)
soup = BeautifulSoup(response.text, 'html.parser')
base_url = f"{urlparse(u…Browse by section
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