[warsaw]

Fixes found while comparing the implementation with the PEP, plus a restructuring of how the protocol code is loaded.

Keyword sorting. A sortable layout with keyword items failed with TypeError: unexpected document node. Keyword items are now sorted by name, after the positional and key/value items, so the output stays valid call syntax: Example('y', 'z', a=10, b=0), never Example(a=10, 'z').

None printer. convert(1, 'p', None) used the default printer, but f'{1!p:{None}}' raised TypeError: 'NoneType' object is not callable. PyObject_Pretty() now treats None like NULL, so all three spellings agree. Interpolation.printer already uses None to mean that no printer was given. The C API docs are updated, and convert() no longer special-cases None.

_pprint_protocol. _load_protocol() and the module __getattr__/__dir__ are gone. The Python half of the protocol (Printer, decompose, Keyword, Entry, Expand, LEAF, DescriptionType and the renderer) now lives at module level in a new private module, Lib/_pprint_protocol.py. pprint re-exports it with lazy from _pprint_protocol import ..., so import pprint alone still imports neither it nor dataclasses, and upstream's test_pprint.test_lazy_import passes unchanged. The C names still come from _pprint. pprint's own function-local imports of dataclasses and re are now lazy imports at the top.

Import cycles. The __pprint__() methods in collections, _collections_abc and dataclasses imported helpers from pprint inside the function. Those helpers are now inlined into the methods, which take Layout, KWARGS, ITEMS and DELEGATE from the C _pprint module with lazy imports. Nothing imports pprint to describe a built-in type any more, so test_lazy_import's forced-eager mode works.

Python/stdlib_module_names.h is regenerated, which also adds the missing _pprint entry.

Tests: test__pprint, test_pprint, test_fstring, test_string, test_tstring, test_dataclasses, test_capi, test_collections, test___all__, test_lazy_import, test_embed, test_site, test_typing, test_enum, test_inspect, test_pydoc and test_sys pass.

🤖 Generated with Claude Code