Python Code
Samples
Copy-ready Python snippets by topic and difficulty — short, focused, and runnable in the browser editor.
How to Create a Mock Headless Browser Screenshot Stub in Python
This code provides a deterministic stub that simulates capturing webpage screenshots with a headless browser, returning formatted output without real browser dependencies.
import subprocess
import sys
def mock_screenshot_webpage(url: str, width: int = 1280, height: int = 800) -> str:
"""Stub that simulates taking a screenshot of a webpage using headless browser."""
# In real implementation, you would use playwright/selenium/headless chrome
result = {
"url": url,
…
How to Merge PDFs in Python (Mock pypdf Stub)
Merge PDF files by concatenating their raw byte content using a simple stubbed class that mimics the pypdf interface.
import io
from hashlib import sha256
class PdfStub:
def __init__(self, data: bytes, name: str):
self.data = data
self.name = name
def get_content_bytes(self) -> bytes:
return self.data
def merge_pdfs_mock(pdf_stubs) -> bytes:
merged = io.BytesIO()
for stub in pdf_stubs:
…
How to Mock a Whisper API Transcription Stub in Python
Simulate an OpenAI Whisper-style transcription response with a dataclass request model and a mock function that returns structured audio transcription output.
import json
from dataclasses import dataclass
from typing import Optional
@dataclass
class AudioRequest:
file_path: str
language: Optional[str] = None
def to_api_payload(self) -> dict:
return {"file": self.file_path, "language": self.language}
def mock_whisper_transcribe(payload: dict) -> dict:
…
Create a Mock GitHub Release API in Python for Testing gh CLI
Build an in-memory GitHub Releases API mock that mimics create_release and list_releases for unit testing gh CLI stubs without network calls.
import json
from unittest.mock import patch, Mock
class GitHubReleaseAPI:
"""Mock GitHub Releases API for testing gh CLI stub behavior."""
def __init__(self):
self.releases = {}
self.counter = 1
def create_release(self, repo, tag, name=None, notes=None):
release_id = self…
Mock Route53 change_resource_record_sets in Python
This code demonstrates how to mock AWS Route53 change_resource_record_sets API calls using the botocore Stubber, allowing you to test DNS update logic without touching real infrastructure.
import boto3
from botocore.exceptions import ClientError
def mock_change_resource_record_sets():
"""Demonstrates Route53 change_resource_record_sets with a mock client."""
# Create a mock Route53 client
route53 = boto3.client('route53', region_name='us-east-1',
aws_access_key_id…
How to Mock a PEP 517 Build Backend in Python
Use unittest.mock.Mock to simulate a PEP 517 backend interface, stub build hooks, and verify calls for package build automation.
import json
from unittest.mock import Mock
# Simulate a PEP 517 backend interface
class Pep517Backend:
def build_wheel(self, wheel_directory, config_settings=None, metadata_directory=None):
return f"{wheel_directory}/mock_package-1.0.0-py3-none-any.whl"
def get_requires_for_build_wheel(self, config_s…
How to Mock and Stub API Calls in Playwright E2E Tests with Python
This code demonstrates how to mock and stub API responses in Playwright end-to-end tests using Python's unittest.mock patch and Playwright's APIRequestContext.
import re
from unittest.mock import patch
from playwright.sync_api import sync_playwright
def verify_api_mock(page, mock_url, mock_response):
with patch("playwright.sync_api.APIRequestContext.get") as mock_get:
mock_get.return_value.json.return_value = mock_response
mock_get.return_value.status_co…
How to Use Stubs, Fakes, Spies, and Mocks in Python Testing
Implement four types of test doubles — stubs, fakes, spies, and mocks — as subclasses of a PaymentGateway interface to replace real dependencies during testing.
class PaymentGateway:
def charge(self, amount):
raise NotImplementedError
class StubPaymentGateway(PaymentGateway):
"""Returns a fixed response without any logic."""
def charge(self, amount):
return {"success": True, "transaction_id": "stub-12345"}
class FakePaymentGateway(PaymentGatewa…
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.