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Python Code Samples

Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.

223 matches
Database scaling & optimization easy

How to Speed Up Column Lookups with DataFrame Index in Python

Use pandas set_index to make repeated column value lookups O(1)-style fast instead of scanning the whole DataFrame each time.

pandas indexing performance
Python
import pandas as pd

# Mock dataset with duplicate customer IDs
data = {"customer_id": [101, 102, 103, 101, 104, 102],
        "order_amount": [250.0, 85.5, 300.0, 175.25, 420.0, 95.75]}

df = pd.DataFrame(data)
df = df.set_index("customer_id")

# Simulated lookup request
search_id = 102

# Fast index-based lookup (no…
16 0 Open
Database scaling & optimization medium

Idempotent Writes for Sharded Databases in Python

Implement a mock shard with idempotent write support using request IDs to prevent duplicate writes and track the latest value per key.

idempotency sharding distributed-systems
Python
import json


class ShardMock:
    """Mock distributed shard with idempotent write support."""

    def __init__(self, shard_id):
        self.shard_id = shard_id
        self._store = {}

    def write(self, key, value, request_id):
        """Write value only if request_id not yet processed; idempotent."""
        i…
14 0 Open
Database scaling & optimization medium

Simulate a GIN Index for JSONB in Python

Build a mock Generalized Inverted Index (GIN) that flattens JSON documents into key-value tokens for fast lookup queries, mimicking PostgreSQL JSONB indexing.

jsonb gin-index inverted-index
Python
import json
import random
from collections import defaultdict

# Mock GIN (Generalized Inverted Index) for JSONB key-value pairs
class GINIndex:
    def __init__(self):
        self.posting_lists = defaultdict(list)  # token -> list of doc_ids
    
    def index(self, doc_id, json_obj):
        """Index a JSON documen…
15 0 Open
Auth & security at scale easy

Fetch Secrets from a Mock Secrets Manager in Python

Build a minimal in-memory secrets manager that stores and retrieves secret values, raising a KeyError for missing names.

secrets-management security mock
Python
import json

class SecretsManager:
    """Mock secrets manager that returns secrets from a local store."""
    
    def __init__(self, store=None):
        self.store = store or {
            "api_key": "mock-api-key-123",
            "db_password": "s3cret-p@ss",
            "jwt_secret": "dev-only-secret"
        }
…
17 0 Open
Auth & security at scale easy

How to Enforce a Strict Referrer Policy in Python

Validate HTTP headers to enforce a strict same-origin Referrer policy, accepting only origin-only URLs or absent Referer values.

referrer security headers
Python
import re
from unittest.mock import patch

def strict_referrer_policy(headers):
    """Return True if Referer header is absent or strictly same-origin."""
    referer = headers.get("Referer")
    if referer is None:
        return True
    # Strict-Origin-When-Cross-Origin allows same-origin full URL
    # but here we…
16 0 Open
Production deployment patterns easy

How to Build a Data Helper for Production Deployment in Python

Build a reusable DataHelper class that loads configs, validates required keys, normalizes string values, and logs schema details — a production-ready data processing pattern.

json pathlib data-processing
Python
import json
from pathlib import Path
from typing import Any, Dict

class DataHelper:
    """Common data processing patterns for production deployment."""
    
    def __init__(self, config_path: str | Path):
        self.config_path = Path(config_path)
        self.config = self._load_config()
    
    def _load_confi…
15 0 Open
Production deployment patterns easy

How to Merge Helm Chart Values Per Environment in Python

Merge default Helm chart values with environment-specific overrides using a recursive dictionary merge function, then write each environment's YAML file.

helm merge yaml
Python
from pathlib import Path
import json
import tempfile


DEFAULT_VALUES = {
    "image": "nginx:latest",
    "replicas": 1,
    "resources": {"cpu": "100m", "memory": "128Mi"},
}

ENV_OVERRIDES = {
    "dev": {"replicas": 1, "resources": {"cpu": "50m"}},
    "staging": {"replicas": 2, "resources": {"cpu": "250m", "memor…
12 0 Open

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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.