Reference library

Python Code Samples

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

11 matches
Errors & debugging medium

How to Add a Correlation ID to Logging Records in Python

Attach a unique correlation ID to every log record using a custom logging.Filter, making distributed request tracking traceable.

logging correlation-id filter
Python
import logging
import uuid
from dataclasses import dataclass, field


@dataclass
class CorrelationIdFilter(logging.Filter):
    correlation_id: str = field(default_factory=lambda: str(uuid.uuid4()))

    def filter(self, record: logging.LogRecord) -> bool:
        record.correlation_id = self.correlation_id
        re…
15 0 Open
Files & data medium

Build a Personal Work Hours Tracker in Python

A Python class that logs daily work hours to a CSV file and produces a weekly summary of total hours worked.

work-hours time-tracking csv
Python
import csv
from pathlib import Path
from datetime import datetime, date

class WorkHoursTracker:
    def __init__(self, file_path="work_hours.csv"):
        self.file_path = Path(file_path)
        if not self.file_path.exists():
            with open(self.file_path, "w", newline="") as f:
                writer = csv…
63 0 Open
Dictionaries & sets medium

How to Implement Disjoint Set Union Find in Python

Implement a Disjoint Set Union-Find data structure using a Python dictionary for parent tracking, with path compression and connectivity checks.

disjoint-set union-find graph
Python
class DisjointSet:
    def __init__(self):
        self.parent = {}

    def find(self, x):
        # Path compression
        if self.parent[x] != x:
            self.parent[x] = self.find(self.parent[x])
        return self.parent[x]

    def union(self, x, y):
        # Initialize if not present
        if x not in…
14 0 Open
Algorithms & data structures medium

Validate Sudoku Board Rows Columns and Boxes in Python

Validate a 9x9 Sudoku board by checking that each row, column, and 3x3 box contains the numbers 1 through 9 exactly once.

sudoku validation matrix
Python
def validate_sudoku(board):
    def is_valid_group(group):
        return sorted(group) == list(range(1, 10))

    def get_columns():
        return [[board[r][c] for r in range(9)] for c in range(9)]

    def get_boxes():
        boxes = []
        for box_row in range(0, 9, 3):
            for box_col in range(0, 9,…
11 0 Open
Automation & scripting medium

Automatically Clean Temporary Files from Applications Using Python

A Python script that safely deletes temporary files from common application temp directories across Windows, Linux, and macOS, tracking cleaned count and disk space.

temporary-files cleanup automation
Python
import os
import shutil
import tempfile
import platform

def clean_application_temp_files():
    """Delete common temporary file locations safely."""
    system = platform.system()
    temp_dirs = []

    if system == "Windows":
        temp_dirs.extend([
            os.path.join(os.getenv("LOCALAPPDATA"), "Temp"),
  …
58 0 Open
Modern tooling medium

How to Enforce Indentation Rules From .editorconfig in Python

A mock function that reads .editorconfig-style indentation rules (spaces or tabs, size) and fixes indentation in source code lines by tracking brace depth.

editorconfig indentation formatting
Python
def enforce_indent(editorconfig_rules, file_content):
    """
    Mock function to enforce indentation rules from .editorconfig.
    Returns the content with indentation fixed (or unchanged if already compliant).
    """
    indent_style = editorconfig_rules.get("indent_style", "spaces")
    indent_size = int(editorco…
14 0 Open
Caching & Redis medium

How to Implement an LFU Cache in Python

Implement a Least Frequently Used (LFU) cache with frequency tracking dictionaries to evict the least accessed items when capacity is reached.

lfu cache frequency
Python
class LFUCache:
    def __init__(self, capacity: int):
        self.capacity = capacity
        self.data = {}
        self.freq = {}
        self.min_freq = 0

    def get(self, key: int) -> int:
        if key not in self.data:
            return -1
        self._increment_freq(key)
        return self.data[key]

  …
12 0 Open
Observability & SRE medium

How to Track Cache Hit Ratio in Python

Simulate an LRU cache with hit/miss tracking and compute a real-time hit ratio from random access patterns.

cache lru hit-ratio
Python
import random
import time
from collections import OrderedDict

class LRUCache:
    def __init__(self, capacity: int):
        self.cache = OrderedDict()
        self.capacity = capacity
        self.hits = 0
        self.misses = 0

    def get(self, key):
        if key in self.cache:
            self.hits += 1
     …
13 0 Open
Microservices patterns medium

How to Handle mTLS Certificate Rotation in Python

Detect mTLS certificate file changes by tracking modification time and hot-reload the SSL context in a running service.

mtls ssl certificate-rotation
Python
import ssl
import tempfile
import datetime
from pathlib import Path


class MTLSContext:
    def __init__(self, cert_path, key_path, ca_path):
        self.cert_path = Path(cert_path)
        self.key_path = Path(key_path)
        self.ca_path = Path(ca_path)
        self.context = None
        self.last_loaded_mtime …
13 0 Open
Microservices patterns medium

How to Mock a Choreography Saga in Python

Simulate a choreography-based saga with event envelopes, status tracking, and compensating actions to model distributed transactions.

saga microservices events
Python
import json
from dataclasses import dataclass, asdict
from typing import List, Optional
from enum import Enum


class SagaStatus(Enum):
    PENDING = "PENDING"
    COMPLETING = "COMPLETING"
    COMPLETED = "COMPLETED"
    FAILED = "FAILED"


@dataclass
class EventEnvelope:
    event_type: str
    order_id: str
    sta…
13 0 Open
ML engineering pipelines medium

How to Mock MLflow Model Registration in Python

Build a lightweight in-memory mock of MLflow's MlflowClient to test model registration, versioning, and stage transitions without a tracking server.

mlflow mocking model-registry
Python
from mlflow.tracking import MlflowClient
from mlflow.entities import ModelVersion, Model


class MockMlflowClient:
    """Minimal mock of MlflowClient's model registration methods."""
    
    def __init__(self):
        self.registered_models = {}
        self.model_versions = {}
    
    def register_model(self, mod…
14 0 Open

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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.