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Modern tooling

uv, ruff, pyproject.toml, packaging, and current Python project workflows.

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Modern tooling medium

Mock Python version with unittest.mock.patch

Use unittest.mock.patch to simulate a specific Python version and test version-dependent behavior.

unittest mock version
Python 
import sys
import unittest
from unittest.mock import patch

class TestPythonVersion(unittest.TestCase):
    @patch("sys.version_info", (3, 9, 0, "final", 0))
    def test_python_version_pinned(self):
        self.assertEqual(sys.version_info[:2], (3, 9))
        print(f"Pinned version: {sys.version_info.major}.{sys.ve…
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Modern tooling — Python code examples

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This page collects modern tooling snippets — short, copy-ready Python you can paste into our free online IDE and run without installing anything. Each sample includes a plain-English explanation and the full source code.

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