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Python Code Samples

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

127 matches
API design & gRPC easy

How to Build a Simple Data Helper in Python for API Design

Create a beginner-friendly DataHelper class that demonstrates basic CRUD operations (add, get, list, remove) using an in-memory dictionary, ideal for learning API design concepts.

api-design data-structures crud
Python
class DataHelper:
    """Simple data helper for beginners learning API design concepts."""
    
    def __init__(self):
        self._data = {}
    
    def add_record(self, key, value):
        """Add a record to the store."""
        self._data[key] = value
        return f"Added: {key} -> {value}"
    
    def get_…
12 0 Open
API design & gRPC easy

How to Build a Simple Filter Helper in Python for API Design

Create a reusable data filter service with dataclasses that mimics gRPC request/response patterns for filtering dataset records.

filtering dataclasses grpc
Python
from dataclasses import dataclass, field
from typing import List, Optional, Dict, Any


@dataclass
class FilterRequest:
    """A simple filter request mirroring a gRPC message structure."""
    field_name: str
    operator: str  # eq, ne, gt, lt, contains
    value: Any
    page_size: int = 10
    page_token: Optional…
13 0 Open
API design & gRPC easy

How to Validate Data in Python for Beginners

A beginner-friendly Python class for validating required fields, types, ranges, and allowed choices in dict payloads.

validation data api
Python
import json
from typing import Any, Dict, List, Optional, Union


class Validator:
    """A simple validate data helper designed for beginners."""

    def __init__(self, data: Union[Dict[str, Any], List[Any]]):
        self.data = data
        self.errors: Dict[str, str] = {}

    def validate_required(self, field: s…
13 0 Open
Streaming & messaging easy

Build a Streaming Messaging Helper in Python

Create a simple message stream class that stores recent messages, sends user messages, and retrieves history or latest messages with timestamps.

streaming deque dataclass
Python
from collections import deque
from dataclasses import dataclass
from datetime import datetime
import time


@dataclass
class Message:
    user: str
    text: str
    timestamp: str = ""

    def __post_init__(self):
        if not self.timestamp:
            self.timestamp = datetime.now().strftime("%H:%M:%S")


class…
13 0 Open
Caching & Redis easy

Cache Data in Redis with Python

A beginner-friendly Redis cache helper that stores JSON strings with a TTL and retrieves them with the redis-py client.

redis cache ttl
Python
import redis


class DataCache:
    def __init__(self, host="localhost", port=6379, db=0):
        self.client = redis.Redis(host=host, port=port, db=db, decode_responses=True)

    def cache_data(self, key, value, ttl=60):
        self.client.setex(key, ttl, value)

    def get_cached_data(self, key):
        return …
15 0 Open
Caching & Redis easy

How to Cache Function Results with Redis in Python

A RedisCache helper class caches function results using a decorator, with JSON serialization and TTL-based expiry.

redis caching decorator
Python
import redis
import json
from functools import wraps

class RedisCache:
    def __init__(self, host='localhost', port=6379, db=0, ttl=60):
        self.client = redis.Redis(host=host, port=port, db=db, decode_responses=True)
        self.ttl = ttl

    def cached(self, key_prefix):
        def decorator(func):
       …
14 0 Open
Caching & Redis easy

How to Use Redis as a Cache in Python

A beginner-friendly RedisCache helper that stores, retrieves, and deletes JSON values with automatic TTL expiration using the redis-py client.

redis cache ttl
Python
import json
import time
import redis


class RedisCache:
    def __init__(self, host="localhost", port=6379, db=0, default_ttl=60):
        self.client = redis.Redis(host=host, port=port, db=db, decode_responses=True)
        self.default_ttl = default_ttl

    def set(self, key, value, ttl=None):
        """Store a v…
11 0 Open
Caching & Redis medium

How to Validate and Cache Data with Redis in Python

A beginner-friendly helper that validates email, phone, and age data and caches validated entries in Redis for 5 minutes.

redis caching validation
Python
import redis
import json
from functools import wraps

class DataValidator:
    def __init__(self, host="localhost", port=6379, db=0):
        self.cache = redis.Redis(host=host, port=port, db=db)
        self.validators = {
            "email": lambda v: "@" in v and "." in v.split("@")[-1],
            "phone": lambd…
15 0 Open
Caching & Redis easy

Redis Cache Helper Class in Python with TTL

Build a DataHelper class that caches function results in Redis with a default TTL, using get_or_set and clear methods.

redis caching cache-aside
Python
import redis
import json
import time


class DataHelper:
    def __init__(self, host="localhost", port=6379, db=0, default_ttl=60):
        self.client = redis.Redis(host=host, port=port, db=db, decode_responses=True)
        self.default_ttl = default_ttl

    def get_or_set(self, key, data_func, ttl=None):
        c…
12 0 Open
Caching & Redis easy

Simple Redis Cache Helper in Python

Build a minimal Redis-backed cache with TTL, JSON serialization, and automated fetching to speed up repeated expensive lookups.

redis caching cache-aside
Python
import time
import redis
import json


class SimpleCache:
    def __init__(self, host="localhost", port=6379, db=0, default_ttl=60):
        self.client = redis.Redis(host=host, port=port, db=db, decode_responses=True)
        self.default_ttl = default_ttl

    def get(self, key):
        value = self.client.get(key)…
10 0 Open
Reliability & rate limiting easy

Rate Limiting with a Simple Python RateLimiter Class

A beginner-friendly Python rate limiter that tracks call timestamps and enforces a maximum number of calls within a rolling time window, with a helper to validate positive integers.

rate-limiting time api
Python
import time

class RateLimiter:
    def __init__(self, max_calls, period_seconds):
        self.max_calls = max_calls
        self.period_seconds = period_seconds
        self.calls = []

    def is_allowed(self):
        now = time.time()
        while self.calls and now - self.calls[0] >= self.period_seconds:
      …
13 0 Open
Observability & SRE easy

Python Observability Data Helper for Beginners

A beginner-friendly Python helper to log events, record metrics, summarize observability data, and export it as JSON.

observability logging metrics
Python
import json
from datetime import datetime
from collections import defaultdict


class ObservabilityDataHelper:
    """Helper for exploring basic observability data patterns."""

    def __init__(self):
        self.events = []
        self.metrics = defaultdict(list)

    def log_event(self, service, level, message):
…
14 0 Open
Observability & SRE easy

Track Success Rates and Latency in Python: SRE Metrics Helper

A beginner-friendly Python class to record request outcomes and latencies, then report success rate, average latency, and p99.

sre metrics latency
Python
import random
import time
from collections import defaultdict


class MetricsTracker:
    """Simple helper to track success rates and latencies for SRE beginners."""

    def __init__(self):
        self.successes = 0
        self.failures = 0
        self.latencies = []

    def record(self, success, latency_ms):
   …
14 0 Open
Microservices patterns easy

How to Build a Microservice Helper in Python

A beginner-friendly Python helper that validates input, normalizes service responses, and simulates user management—showing clean patterns for microservice development.

microservices validation oop
Python
import json
from typing import Any, Dict, List


class DataValidator:
    """Simple validator for common data patterns."""

    @staticmethod
    def is_valid_email(value: str) -> bool:
        """Check if value looks like an email."""
        return "@" in value and "." in value.split("@")[-1]

    @staticmethod
    …
12 0 Open
Microservices patterns easy

How to Implement a Data Helper for Microservices in Python

Create a reusable helper class to serialize, deserialize, and wrap data for microservice communication using dataclasses and JSON.

microservices json dataclass
Python
import json
from dataclasses import dataclass, asdict
from typing import Any, Dict, List


@dataclass
class ServiceResponse:
    status: str
    data: Any
    message: str = ""


class DataHelper:
    """Simple helper for microservice data handling."""

    @staticmethod
    def serialize(data: Dict[str, Any]) -> str:…
13 0 Open
Big data & Spark easy

Modeling a Hive Metastore Table Schema in Python

A dataclass that mimics a Hive metastore table schema—columns, partition keys, storage format, and location—with helper methods for description and mutation.

hive dataclass metastore
Python
from dataclasses import dataclass, field
from typing import Dict, List, Optional


@dataclass
class HiveTable:
    """Simple mock of a Hive metastore table schema."""
    name: str
    database: str = "default"
    columns: List[Dict[str, str]] = field(default_factory=list)
    partition_keys: List[Dict[str, str]] = f…
14 0 Open
ML engineering pipelines easy

Build a Data Helper Class in Python for ML Pipelines

A beginner-friendly Python class that summarizes, filters, and exports ML dataset rows as JSON.

data-helper ml-pipeline json
Python
from typing import List, Dict, Any
import json

class DataHelper:
    """Beginner-friendly helpers for ML data pipelines."""
    
    def __init__(self, data: List[Dict[str, Any]]):
        self.data = data
        self.keys = list(data[0].keys()) if data else []
    
    def summary(self) -> Dict[str, Any]:
        "…
16 0 Open
ML engineering pipelines medium

How to Create a Mock ONNX Model in Python

Build and export a minimal mock ONNX model with a Reshape and Gemm layer using the onnx helper API.

onnx model-export mlops
Python
import onnx
import numpy as np
from onnx import helper, TensorProto

def create_mock_model():
    # Define input and output tensors
    input_tensor = helper.make_tensor_value_info('input', TensorProto.FLOAT, [1, 3, 224, 224])
    output_tensor = helper.make_tensor_value_info('output', TensorProto.FLOAT, [1, 10])

   …
16 0 Open
ML engineering pipelines easy

How to Load, Save, and Split JSON Data in Python

Provides helper functions to load, save, and split JSON dictionary data for simple ML pipeline preprocessing.

json data-splitting ml-pipeline
Python
import json
from pathlib import Path


def load_json_data(file_path):
    """Load JSON data from a file, returning an empty dict if missing."""
    path = Path(file_path)
    if path.exists():
        with path.open("r", encoding="utf-8") as f:
            return json.load(f)
    return {}


def save_json_data(data, f…
13 0 Open
Database scaling & optimization medium

Database Helper in Python with SQLite Scaling Optimization

Build a beginner-friendly SQLite database helper class with WAL, indexed queries, and efficient batch inserts for scaling.

sqlite database scalability
Python
import sqlite3
from contextlib import contextmanager


class DatabaseHelper:
    """Beginner-friendly helper for SQLite database operations with scaling tips."""

    def __init__(self, db_path):
        self.db_path = db_path

    @contextmanager
    def connection(self):
        """Context manager for automatic comm…
14 0 Open
Database scaling & optimization easy

How to Convert Data with Scaling for Database Optimization in Python

A beginner-friendly helper that normalizes and scales numeric fields in a list of dicts, reducing storage footprint for database efficiency.

data conversion database scaling
Python
import json
from datetime import datetime

def convert_data(data: list[dict], scale_factor: int = 1) -> list[dict]:
    """Convert a list of dicts to a scaled, normalized format for database efficiency."""
    converted = []
    for row in data:
        normalized = {}
        for key, value in row.items():
          …
14 0 Open
Database scaling & optimization easy

How to Create a Data Helper Class in Python for JSON Files

Build a beginner-friendly Python helper class to read, write, filter, and summarize JSON data files with clean, reusable methods.

json data-helper file-io
Python
import json
from pathlib import Path


class DataHelper:
    """Simple beginner-friendly helper for reading and writing JSON data files."""

    @staticmethod
    def read_json(filename):
        file_path = Path(filename)
        if file_path.exists():
            with file_path.open("r", encoding="utf-8") as f:
    …
13 0 Open
Database scaling & optimization easy

How to Create a Database Helper Class for Beginners in Python

Build a beginner-friendly SQLite helper class with indexing and batch inserts to optimize database queries in Python.

sqlite database indexing
Python
import sqlite3


class DatabaseHelper:
    def __init__(self, db_path):
        self.connection = sqlite3.connect(db_path)
        self.cursor = self.connection.cursor()

    def create_table_with_index(self, table_name, columns, indexed_column):
        columns_sql = ", ".join(f"{name} {dtype}" for name, dtype in col…
13 0 Open
Database scaling & optimization easy

How to Optimize SQLite Database Performance in Python

A Python helper that creates an index, enables WAL mode, and tunes synchronous settings to optimize SQLite database performance.

sqlite database optimization
Python
import sqlite3

DATABASE_PATH = "beginners.db"
UNOPTIMIZED_TABLE_SCHEMA = """
CREATE TABLE IF NOT EXISTS users (
    id INTEGER PRIMARY KEY,
    name TEXT NOT NULL,
    email TEXT NOT NULL
)
"""


def optimize_database(db_path: str = DATABASE_PATH) -> dict:
    with sqlite3.connect(db_path) as connection:
        curs…
14 0 Open

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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.