Reference library

Python Code Samples

Medium snippets you can copy, study, and run in the browser editor.

5 matches
Files & data medium

How to Automatically Merge Hundreds of Excel Files Without Losing Formatting in Python

Merge all .xlsx files in a folder into a single Excel workbook, preserving individual sheet structures with sheet name prefixes.

excel pandas merge
Python
import pandas as pd
from pathlib import Path

def merge_excel_files(folder_path: str, output_path: str) -> None:
    """
    Merge all .xlsx files in a folder into a single Excel file,
    preserving individual sheet structures.
    """
    folder = Path(folder_path)
    excel_files = list(folder.glob("*.xlsx"))
    
…
47 0 Open
Algorithms & data structures medium

Product of All Elements Except Self in Python

Given a list of integers, return a list where each element is the product of all other elements except itself, using prefix and suffix products in O(n) time and O(1) extra space.

array prefix suffix
Python
def product_except_self(nums):
    n = len(nums)
    result = [1] * n
    
    left_product = 1
    for i in range(n):
        result[i] = left_product
        left_product *= nums[i]
    
    right_product = 1
    for i in range(n - 1, -1, -1):
        result[i] *= right_product
        right_product *= nums[i]
    
…
14 0 Open
Algorithms & data structures medium

Product of Array Except Self in Python Without Division

Compute the product of all array elements except the current one in O(n) time using prefix and suffix products, without using division.

arrays prefix-product suffix-product
Python
from math import prod


def product_except_self(nums):
    n = len(nums)
    result = [1] * n
    left_product = 1
    for i in range(n):
        result[i] = left_product
        left_product *= nums[i]

    right_product = 1
    for i in range(n - 1, -1, -1):
        result[i] *= right_product
        right_product *…
14 0 Open
Git + Python medium

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.

git release-notes automation
Python
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,
   …
49 0 Open
Database scaling & optimization medium

Composite index leftmost prefix in Python

Simulate a composite index in SQLite and check whether query columns match the leftmost prefix rule for index usage.

sqlite indexes database
Python
import sqlite3


def get_indexed_columns(table_name):
    """Simulate a composite index by reading column names that start with 'idx_'."""
    conn = sqlite3.connect(":memory:")
    conn.execute(f"CREATE TABLE {table_name} (id INTEGER, idx_col1 TEXT, idx_col2 INTEGER, other TEXT)")
    conn.execute(f"CREATE INDEX idx_…
15 0 Open

Browse by section

Each section groups closely related Python snippets.

Guide: free Python code samples library

Copy-ready Python snippets for learners and developers

PythonSkillset code samples are short, focused examples organised by topic and difficulty. Every snippet is server-rendered HTML — readable by search engines and easy to copy. Open any sample, read the notes, copy the code, then press Try in editor to run it in the browser with Pyodide.

How to use this library

  1. Pick a topic section — strings, lists, files, functions, and more
  2. Open a sample, read How it works, and copy the code block
  3. Run it in the IDE, tweak values, then take a related quiz or tutorial lesson

Samples vs tutorials and challenges

Samples are quick reference — one concept per page. For step-by-step teaching, use our Python tutorials. To test yourself, try quizzes or coding challenges. Clean up style with the Python formatter.