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Python Code Samples

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

4 matches
Modern tooling easy

How to Parametrize Tests in Python with pytest

This code demonstrates how to use pytest's @pytest.mark.parametrize decorator to run a single test function against multiple input sets, ensuring comprehensive coverage with minimal code duplication.

pytest parametrize testing
Python 
import pytest


def multiply(a, b):
    return a * b


@pytest.mark.parametrize("x, y, expected", [
    (2, 3, 6),
    (4, 5, 20),
    (0, 10, 0),
    (7, 1, 7),
])
def test_multiply(x, y, expected):
    result = multiply(x, y)
    assert result == expected, f"multiply({x}, {y}) = {result}, expected {expected}"


if _…
15 0 Open
Modern tooling easy

How to Run Coverage Report and Generate HTML in Python

Use the coverage module to measure test coverage, save the report, and generate an HTML report in Python.

coverage testing unittest
Python 
import coverage
import unittest


def add(a, b):
    return a + b


class TestAdd(unittest.TestCase):
    def test_add_positive(self):
        self.assertEqual(add(2, 3), 5)


if __name__ == "__main__":
    cov = coverage.Coverage(source=["__main__"])
    cov.start()
    suite = unittest.defaultTestLoader.loadTestsFro…
12 0 Open
Modern tooling medium

How to set up mypy strict mode in Python

Demonstrates how to configure and run mypy in strict mode to enforce full type annotation coverage across a Python project.

mypy type-hints strict-mode
Python 
from typing import Dict, Optional


def describe_user(name: str, age: int, email: Optional[str] = None) -> Dict[str, object]:
    """Build a user description dictionary with strict type annotations."""
    user: Dict[str, object] = {"name": name, "age": age}
    if email is not None:
        user["email"] = email
    …
14 0 Open
Testing & modern typing medium

How to Run Test Coverage with pytest-cov in Python

Run pytest with coverage reporting using pytest-cov on a temporary project and see line-by-line coverage output.

pytest coverage testing
Python 
import os
import subprocess
import tempfile
from pathlib import Path


def sample_function(x: int) -> int:
    """A simple function to demonstrate coverage."""
    if x > 0:
        return x * 2
    else:
        return -x


def run_pytest_with_coverage() -> str:
    """Run pytest with coverage on a temp project and r…
14 0 Open

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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.

Related coding tools

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