Chapter 11

[henrydingliu]

Summary of Changes

Related GitHub Issue(s)

Additional Context for Reviewers

Checklist

• I passed tests locally for both code (uv run pytest) and documentation changes (uv run --directory docs jb build . --builder=custom --custom-builder=doctest)

---

Note

Low Risk
Changes are documentation and formatting with no intentional behavior changes; residual risk is only if an unused import removal or notebook edit accidentally altered a calculation, which the existing exhibit asserts are meant to catch.

Overview
Adds and reformats the Friedland Chapter 11 documentation notebook (docs/friedland/chapter_11.ipynb), walking through frequency–severity exhibits with the same helper patterns used in other Friedland chapters. The notebook cells are largely style-only updates (Black/Ruff-friendly layout, double quotes, wrapped lines); exhibit logic and golden assert checks are preserved, with # ruff: noqa: E241 where aligned numeric literals are intentional.

Supporting changes are minor: TriangleWeight drops an unused sparse import and gets whitespace/type-hint formatting (including the existing full-triangle n_periods weight path, still covered by test_triangleweight_full_triangle). WeightedRegression and test_utilities.py pick up the same lint-driven tweaks (e.g. assert options.AUTO_SPARSE, rename l → latest in a concat immutability test).

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[github-actions]

Pyright Type Completeness

View the full pyright --verifytypes output for this commit

Project (full chainladder package, at this PR's head): 15.1% of exported symbols fully typed (209 / 1380)

	Known	Ambiguous	Unknown	Total
Project (head)	209	112	1059	1380

Other symbols referenced but not exported by chainladder: 13

	Known	Ambiguous	Unknown	Total
Other (head)	3	1	9	13

Symbols without documentation:

• Functions without docstring: 325
• Functions without default param: 0
• Classes without docstring: 10

Patch (exported symbols added or changed by this PR): no exported symbol type-completeness changes detected.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.75%. Comparing base (efaec4c) to head (ea5c34e).
⚠️ Report is 8 commits behind head on chapter_11_parking.

Additional details and impacted files

@@                  Coverage Diff                   @@
##           chapter_11_parking    #1271      +/-   ##
======================================================
- Coverage               91.75%   91.75%   -0.01%     
======================================================
  Files                      93       93              
  Lines                    5448     5447       -1     
  Branches                  702      702              
======================================================
- Hits                     4999     4998       -1     
  Misses                    326      326              
  Partials                  123      123              

Flag	Coverage Δ
unittests	91.75% <100.00%> (-0.01%)	⬇️

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