Python Code
Samples
Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
How to Use the breakpoint() Function for Interactive Debugging in Python
Insert a breakpoint() call into your code to drop into an interactive debugger session where you can inspect variables and step through execution.
def calculate_total(prices, discount=0):
"""Calculates total price with optional discount."""
subtotal = sum(prices)
breakpoint() # Interactive debugging session starts here
final_total = subtotal * (1 - discount)
return final_total
if __name__ == "__main__":
items = [25.50, 13.25, 9.99, 5.7…Group Python Events into Sessions with a Gap Timeout
Groups timestamped events into sessions, starting a new session when the time gap exceeds a specified timeout.
from itertools import groupby
from datetime import datetime, timedelta
def session_window_group(events, gap_seconds=300):
"""Group events into sessions where gap > gap_seconds starts a new session."""
if not events:
return []
events = sorted(events, key=lambda x: x[0])
sessions = []
c…How to Define Nox Sessions in Python
Automate repetitive tasks like testing and linting with reusable Nox sessions.
import nox
@nox.session(python=["3.9", "3.10"])
def tests(session):
session.install("pytest")
session.run("pytest")
@nox.session(python="3.9")
def lint(session):
session.install("ruff")
session.run("ruff", "check", ".")
if __name__ == "__main__":
print("Nox sessions defined: tests, lint")
…How to Share Fixtures Across Tests with pytest conftest
Learn how to define pytest fixtures in conftest.py and control their scope (function, module, session) so every test in a directory reuses the same setup and teardown.
import pytest
@pytest.fixture
def sample_data():
"""Simple fixture available to all tests in this directory."""
return {"name": "Alice", "age": 30}
@pytest.fixture(scope="session")
def session_data():
"""Fixture created once per test session."""
return {"session_id": 12345}
@pytest.fixture(scope="mo…How to Track Session Windows with Gap Timeout in Python
A Python class that groups events into sessions, closing a session when the gap between events exceeds a timeout threshold.
import time
class SessionWindow:
"""Track sessions with a gap timeout (mock)."""
def __init__(self, timeout_seconds=5):
self.timeout = timeout_seconds
self.session_start = None
self.last_event_time = None
self.event_count = 0
self.events = []
def add_event…How to Mock a Redis Session Store Cookie SID in Python
Mock a Redis-backed session store with a cookie-based session ID (SID) in Python, including the create, read, and delete operations.
import redis
import uuid
import time
class RedisSessionStore:
def __init__(self, host="localhost", port=6379, db=0, prefix="session:"):
self.client = redis.Redis(host=host, port=port, db=db)
self.prefix = prefix
def create_session(self, timeout_seconds=3600):
session_id = uuid.uuid4(…Session window gap mock in Python
Group sorted timestamps into sessions where any gap between consecutive events exceeds a threshold starts a new session.
from datetime import datetime, timedelta
def session_windows(timestamps, gap_seconds=300):
"""Group timestamps into sessions where gaps > gap_seconds start new sessions."""
if not timestamps:
return []
# Sort timestamps chronologically to ensure correct windowing
timestamps = sorted(timestam…How to Mock Sticky Session Read-Your-Writes in Python
Simulates a sticky session store that routes reads for a session to the node where the last write occurred, demonstrating read-your-writes consistency.
class StickySessionStore:
def __init__(self):
self.data = {}
self.session_nodes = {}
def write(self, session_id, key, value):
self.data[key] = value
self.session_nodes[session_id] = key
return f"Wrote {key}={value} for session {session_id}"
def read(self, session_i…How to Create Secure Session Cookies in Python with Secure, HttpOnly, and SameSite Flags
This code demonstrates how to create a secure session cookie using Python's stdlib, setting Secure, HttpOnly, and SameSite attributes to protect against common web vulnerabilities.
import http.cookies
import secrets
class SessionManager:
def __init__(self):
self.cookie = http.cookies.SimpleCookie()
def create_session_cookie(self, session_id=None):
session_id = session_id or secrets.token_hex(16)
self.cookie["session"] = session_id
self.cookie["session"][…How to Mock a Redis Session Store in Python
An in-memory RedisSessionStore class with TTL-based expiry, get/set/delete/exists methods, and JSON field support—perfect for testing and prototyping without a live Redis.
import time
import json
from collections import defaultdict
class RedisSessionStore:
"""In-memory mock of a Redis-backed session store."""
def __init__(self, ttl=3600):
self._data = defaultdict(dict)
self._expires = {}
self._ttl = ttl
def set(self, session_id, field, value):
…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
- Pick a topic section — strings, lists, files, functions, and more
- Open a sample, read How it works, and copy the code block
- 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.