Reference library

Python Code Samples

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

8 matches
Errors & debugging medium

How to Log Errors with Structured Fields in Python

Logs error details as structured dictionary fields using Python's logging module with extra parameters.

logging errors structured
Python
import logging
import sys

def log_structured_error(operation: str, user_id: int, status_code: int, error_msg: str):
    """Log an error with structured fields using a dictionary."""
    logger = logging.getLogger("structured_logger")
    logger.setLevel(logging.ERROR)
    
    # Create console handler if not already …
14 0 Open
Errors & debugging medium

How to attach a request ID to exception messages in Python

This code shows how to enrich exception messages with contextual request IDs using context variables, making error logs more traceable across concurrent requests.

contextvars exception-handling logging
Python
import logging
from contextvars import ContextVar

request_id_var = ContextVar("request_id", default="unknown")

def add_request_id(exc: Exception) -> Exception:
    exc.args = (f"request_id={request_id_var.get()} | {exc.args[0]}" if exc.args else f"request_id={request_id_var.get()}",) + exc.args[1:]
    return exc

d…
12 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…
60 0 Open
AI & LLM integration patterns medium

Parse ReAct Logs into Thought Action Observation Steps in Python

Parse a ReAct agent's textual log into structured steps with thought, action, and observation using regex and named tuples.

react regex llm
Python
import re
from collections import namedtuple


ReActStep = namedtuple("ReActStep", ["thought", "action", "observation"])


def parse_react_log(log: str) -> list[ReActStep]:
    """Parse a ReAct log into structured thought/action/observation steps."""
    pattern = re.compile(
        r"Thought:\s*(?P<thought>.+?)\s*"
…
13 0 Open
Automation & scripting medium

Python: Archive Old Logs by Compressing Gzip by Age

A Python script that finds .log files older than a specified age and compresses them into .gz archives while removing the originals.

gzip log-rotation automation
Python
import gzip
import os
import shutil
from pathlib import Path


def archive_logs(log_dir: str, max_age_days: int) -> list[str]:
    """Compress log files older than max_age_days into .gz archives.
    
    Returns a list of compressed file paths.
    """
    cutoff = time.time() - max_age_days * 86400
    compressed = …
14 0 Open
Automation & scripting medium

Track Internet Connectivity and Downtime Automatically in Python

Monitors internet connectivity by pinging a remote host and logs any downtime events with timestamps and duration.

internet connectivity monitoring
Python
import time
import subprocess
from datetime import datetime

def check_internet(host="8.8.8.8", timeout=3):
    """Returns True if internet is reachable via ping."""
    try:
        subprocess.run(
            ["ping", "-c", "1", "-W", str(timeout), host],
            capture_output=True,
            timeout=timeout …
39 0 Open
System design patterns medium

How to Build a Sidecar Logging Proxy in Python

Wrap any object with a proxy that transparently logs every method call, arguments, return value, and execution time to a file — mimicking a sidecar pattern.

proxy logging sidecar
Python
import logging
import time
from datetime import datetime


class LoggingProxy:
    """Sidecar-style proxy that logs all calls to a wrapped object."""

    def __init__(self, target, log_file="proxy.log"):
        self._target = target
        logging.basicConfig(
            filename=log_file,
            level=loggin…
15 0 Open
A/B testing & experimentation medium

How to join assignment logs with outcomes in Python

Merge submission log entries with grading outcomes using left join and full outer join patterns in pure Python.

join data-merge ab-testing
Python
from datetime import datetime, timedelta

class AssignmentLog:
    def __init__(self):
        self.logs = [
            {"assignment_id": 101, "student_id": "S001", "submitted_at": "2024-03-01 10:30:00"},
            {"assignment_id": 101, "student_id": "S002", "submitted_at": "2024-03-02 14:15:00"},
            {"as…
12 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.