Implement longest_positive_streak with tests and CI

.github/workflows/pytest.yml

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+name: Pytest
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ["3.8", "3.9", "3.10"]
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v3
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install pytest
+    - name: Test with pytest
+      run: |
+        PYTHONPATH=. pytest

streak.py

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+from typing import List
+
+def longest_positive_streak(nums: List[int]) -> int:
+    """
+    Calculates the length of the longest run of consecutive values
+    strictly greater than 0.
+
+    Args:
+        nums: A list of integers.
+
+    Returns:
+        The length of the longest streak of positive numbers.
+    """
+    max_streak = 0
+    current_streak = 0
+    for num in nums:
+        if num > 0:
+            current_streak += 1
+        else:
+            max_streak = max(max_streak, current_streak)
+            current_streak = 0
+    max_streak = max(max_streak, current_streak)
+    return max_streak

tests/test_streak.py

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+import pytest
+from streak import longest_positive_streak
+
+def test_empty_list():
+    """
+    Test that an empty list returns a streak of 0.
+    """
+    assert longest_positive_streak([]) == 0
+
+def test_multiple_streaks():
+    """
+    Test that the function returns the longest of multiple streaks.
+    """
+    assert longest_positive_streak([2, 3, -1, 5, 6, 7, 0, 4]) == 3
+
+def test_all_positive():
+    """
+    Test a list where all numbers are positive.
+    """
+    assert longest_positive_streak([1, 2, 3, 4, 5]) == 5
+
+def test_all_non_positive():
+    """
+    Test a list with no positive numbers.
+    """
+    assert longest_positive_streak([-1, -2, 0, -5]) == 0
+
+def test_single_element_positive():
+    """
+    Test a list with a single positive number.
+    """
+    assert longest_positive_streak([5]) == 1
+
+def test_single_element_non_positive():
+    """
+    Test a list with a single non-positive number.
+    """
+    assert longest_positive_streak([-5]) == 0
+
+def test_streak_at_the_end():
+    """
+    Test a list where the longest streak is at the end.
+    """
+    assert longest_positive_streak([-1, 0, 1, 2, 3, 4]) == 4
+
+def test_streak_at_the_beginning():
+    """
+    Test a list where the longest streak is at the beginning.
+    """
+    assert longest_positive_streak([1, 2, 3, 4, -1, 0]) == 4
+
+def test_zeros_and_negatives():
+    """
+    Test a list containing a mix of zeros and negative numbers.
+    """
+    assert longest_positive_streak([1, 2, 0, 3, 4, -5, 6]) == 2