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How to compute exact match metric in Python
Computes the exact match (EM) metric for LLM outputs by normalizing text and comparing predictions against references.
def compute_exact_match(predictions, references):
def normalize(text):
import re
text = text.lower().strip()
text = re.sub(r'\b(a|an|the)\b', ' ', text)
text = re.sub(r'[^a-z0-9\s]', '', text)
text = ' '.join(text.split())
return text
matches = sum(1 for pred, r…How to hash a prompt with SHA-256 in Python
Create a SHA-256 hex fingerprint of a prompt string, with a short-prefix variant for quick references.
import hashlib
def prompt_hash_fingerprint(prompt: str) -> str:
"""Return the full SHA-256 hex digest of the prompt."""
return hashlib.sha256(prompt.encode("utf-8")).hexdigest()
def short_fingerprint(prompt: str, length: int = 12) -> str:
"""Return a short prefix of the SHA-256 digest for quick reference…How to parse JSON in Python: A Beginner's Guide with Code Examples
This guide shows you how to parse JSON data in Python step by step, with practical code examples and expected outputs.
import json
from typing import Any, Dict, List, Optional
class DataHelper:
"""Beginner-friendly helper for common AI/LLM data tasks."""
def __init__(self, data: Optional[Dict[str, Any]] = None):
self.data = data or {}
def to_prompt(self, template: str) -> str:
"""Format a prompt…How to randomly assign a prompt variant to each key in Python
Randomly pick one variant from a list for each prompt key, useful for A/B testing message variations.
import random
def assign_prompt_variant(prompts: dict[str, list[str]]) -> dict[str, str]:
"""Assign a random prompt variant to each prompt key."""
return {key: random.choice(variants) for key, variants in prompts.items()}
if __name__ == "__main__":
prompt_bank = {
"greeting": ["Hello!", "Hi there…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 Automatically Download Every Favicon from a List of Websites in Python
Download each website's favicon.ico file by constructing its URL, making a GET request, and saving the binary content locally.
import requests
from urllib.parse import urlparse
import os
websites = [
"https://www.google.com",
"https://www.github.com",
"https://www.stackoverflow.com"
]
def download_favicon(url):
parsed = urlparse(url)
favicon_url = f"{parsed.scheme}://{parsed.netloc}/favicon.ico"
response = requests.g…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 Batch Resize Images in Python with pathlib and Pillow
Batch resize all JPG images from a source folder and save to a destination folder using pathlib and Pillow.
from pathlib import Path
from PIL import Image
def batch_resize_images(src_dir: str, dest_dir: str, size: tuple[int, int] = (800, 600)) -> None:
src_path = Path(src_dir)
dest_path = Path(dest_dir)
dest_path.mkdir(parents=True, exist_ok=True)
for img_path in src_path.glob("*.jpg"):
if not …How to Build a CLI with argparse in Python
Create a beginner-friendly command-line tool in Python that processes multiple filenames with optional flags for verbose output and uppercase conversion.
import argparse
def main():
parser = argparse.ArgumentParser(
description="A simple CLI to process files with optional verbose mode."
)
parser.add_argument("filenames", nargs="+", help="Files to process")
parser.add_argument("-v", "--verbose", action="store_true", help="Print extra details")
…How to Build a Docker Image Tag Script in Python
Generate consistent Docker image tags from service names and versions with automatic normalization.
#!/usr/bin/env python3
"""Mock script for building docker image tags."""
def build_tag(service_name: str, version: str, registry: str = "docker.io") -> str:
"""Construct a docker image tag."""
safe_name = service_name.lower().replace("_", "-")
return f"{registry}/{safe_name}:{version}"
if __name__ == "…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 Python CLI with argparse
Create a friendly command-line greeting tool with argparse that accepts a positional name and optional flags for custom greetings and uppercase output.
import argparse
def greet(name, greeting="Hello", uppercase=False):
message = f"{greeting}, {name}!"
return message.upper() if uppercase else message
if __name__ == "__main__":
parser = argparse.ArgumentParser(
description="A simple greeting tool to demonstrate argparse basics."
)
parser.…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 a Simple argparse CLI in Python
Build a beginner-friendly command-line tool with argparse that greets a user, with optional greeting text and uppercase output.
import argparse
def greet(name, greeting="Hello", uppercase=False):
message = f"{greeting}, {name}!"
if uppercase:
message = message.upper()
return message
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Simple CLI greeting tool")
parser.add_argument("name", help=…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 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 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 Clean Old Temp Files in Python
A Python script that scans a directory and deletes files older than a configurable age (default: one week), with safe error handling.
import os
import time
from pathlib import Path
def clean_old_temp_files(directory=".", max_age_seconds=7 * 24 * 60 * 60):
"""
Remove files in directory older than the specified age.
Args:
directory: Path to directory to clean
max_age_seconds: Maximum age in seconds (default: 1 week)
…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 Mock Headless Browser Screenshot Stub in Python
This code provides a deterministic stub that simulates capturing webpage screenshots with a headless browser, returning formatted output without real browser dependencies.
import subprocess
import sys
def mock_screenshot_webpage(url: str, width: int = 1280, height: int = 800) -> str:
"""Stub that simulates taking a screenshot of a webpage using headless browser."""
# In real implementation, you would use playwright/selenium/headless chrome
result = {
"url": url,
…How to Create a Password Protected Zip Archive in Python
Generate a password-protected zip archive and verify password correctness using the standard library zipfile module.
import zipfile
import tempfile
import os
def create_password_protected_zip(zip_path, password: str, files: dict):
"""
Create a zip archive with password protection (mock encryption).
Args:
zip_path: Path where the zip file will be created
password: Password for the archive
files:…How to Create a Simple Python CLI with argparse
Build a beginner-friendly command-line tool with argparse that accepts positional and optional arguments to greet users flexibly.
import argparse
def greet(name, greeting="Hello", uppercase=False):
message = f"{greeting}, {name}!"
return message.upper() if uppercase else message
def main():
parser = argparse.ArgumentParser(
description="A simple CLI tool that greets users."
)
parser.add_argument(
"name",
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