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Testing & modern typing

pytest basics, mocks, type hints, TypedDict, Protocol, and static-checking patterns.

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How to Verify Formatted Output with an Approval Test in Python

Write a small Python approval test that verifies a function's exact formatted output using unittest.

approval-testing unittest formatting
Python 
import sys
from io import StringIO
import unittest

def generate_output(name, score):
    return f"Player: {name} | Score: {score:03d}"

class TestFormattedOutput(unittest.TestCase):
    def test_output_format(self):
        expected = "Player: Alice | Score: 042"
        result = generate_output("Alice", 42)
        …
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