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Implement PEP 814 frozendict - #8951

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RustPython:mainfrom
youknowdot:cpython-315-frozendict
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Implement PEP 814 frozendict#8951
youknowdot wants to merge 1 commit into
RustPython:mainfrom
youknowdot:cpython-315-frozendict

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@youknowdot

@youknowdot youknowdot commented Oct 2, 2026

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Summary

Implement the builtin frozendict from PEP 814, characterized against CPython 3.15.0rc2.

  • Own immutable dictionary storage directly, with shared dict views/iterators, cached order-independent hashing, subclass-aware construction and unions, copy/deepcopy, pickle, and GC support
  • Support frozen globals in eval/exec and frame/function APIs, preserving readonly function.__globals__ member layout; accept frozen type namespaces through a mutable class-namespace copy
  • Extend existing dictionary C-API reads and eval/frame APIs; reject writes without exposing mutable backing storage
  • Add 58 original Python regressions exercised by four Rust integration tests, and remove two now-passing dict expected-failure markers without changing their assertions

The C-API work follows this crate's abi3/abi3t scope. New non-limited CPython PyFrozenDict_* exports and type statics remain outside its current ABI architecture.

Validation

  • Workspace Rust tests: 1,349 passed, 18 ignored
  • C-API tests: 120 passed, 4 ignored
  • All 58 original regressions pass on RustPython and CPython 3.15.0rc2, with no skips
  • 39 unchanged rc2 dict/view/copy tests: pass, with one upstream CPython-only skip; equivalent hashing assertions also run in the native suite
  • Release stdlib tests: 831 tests across dict, dictviews, copy, builtin, types, funcattrs, frame, generators, coroutines, and asyncgen; 43 existing skips
  • Full snippet run: 467 passed, 13 failed. Twelve failures are sandbox multiprocessing/filesystem restrictions also observed with host CPython; one needs the optional SQLite feature omitted by the default build
  • Workspace and C-API Clippy: clean; normal pre-commit hooks pass
  • The limited-stack deep-repr and nested-map stress crashes in unoptimized dev mode also reproduce on an exact clean base build; both pass in the feature's optimized test/release builds

AI-assisted with OpenAI Codex: implementation, regression tests, review, and local validation.

@youknowdot
Implement PEP 814 frozendict
b203807 
Add dictionary-owned frozen mapping storage, shared views and cached hashing, read-only execution globals, type namespace support, and stable dictionary C-API coverage. Add differential regressions against CPython 3.15rc2.

Assisted-by: Codex:model-version-unavailable
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📦 Library Dependencies

The following Lib/ modules were modified. Here are their dependencies:

[x] test: cpython/Lib/test/test_dict.py (TODO: 2)
[x] test: cpython/Lib/test/test_dictcomps.py (TODO: 1)
[x] test: cpython/Lib/test/test_dictviews.py (TODO: 1)
[x] test: cpython/Lib/test/test_userdict.py
[x] test: cpython/Lib/test/mapping_tests.py

dependencies:

dependent tests: (no tests depend on dict)

[ ] lib: cpython/Lib/copy.py
[x] test: cpython/Lib/test/test_copy.py

dependencies:

  • copy
    • copyreg, types, weakref

dependent tests: (324 tests)

  • copy: test_array test_ast test_bytes test_code test_codecs test_collections test_copy test_copyreg test_coroutines test_csv test_decimal test_defaultdict test_deque test_descr test_dictviews test_email test_enum test_exceptions test_fractions test_frame test_functools test_generators test_genericalias test_http_cookies test_inspect test_ipaddress test_itertools test_logging test_memoryview test_minidom test_opcache test_optparse test_ordered_dict test_platform test_plistlib test_posix test_re test_set test_site test_slice test_statistics test_structseq test_super test_sysconfig test_tomllib test_types test_typing test_unittest test_urllib2 test_uuid test_weakref test_weakset test_xml_dom_minicompat test_xml_etree test_zlib
    • argparse: test_argparse
      • ast: test_builtin test_codeop test_compile test_compiler_codegen test_dis test_fstring test_future_stmt test_peepholer test_peg_generator test_ssl test_type_comments test_ucn test_unparse
      • calendar: test_calendar test_imaplib test_strftime
      • compileall: test_compileall
      • dis: test__opcode test_compiler_assemble test_dtrace test_monitoring test_patma test_positional_only_arg test_type_cache
      • ensurepip: test_ensurepip test_venv
      • gzip: test_fileinput test_tarfile test_xmlrpc
      • http.server: test_httpservers test_robotparser test_urllib2_localnet
      • inspect: test_abc test_asyncgen test_buffer test_clinic test_grammar test_ntpath test_operator test_posixpath test_pydoc test_signal test_sqlite3 test_traceback test_turtle test_type_annotations test_type_params test_yield_from test_zipimport test_zipimport_support test_zoneinfo
      • mimetypes: test_mimetypes
      • pdb: test_pdb
      • pickle: test_annotationlib test_asyncio test_bool test_bz2 test_concurrent_futures test_configparser test_ctypes test_dict test_enumerate test_importlib test_io test_iter test_list test_lzma test_memoryio test_os test_pathlib test_pickle test_picklebuffer test_pickletools test_random test_range test_shelve test_socket test_str test_string test_time test_trace test_tuple test_type_aliases test_unittest test_xpickle test_zipfile test_zoneinfo
      • platform: test__locale test__osx_support test_asyncio test_baseexception test_cmath test_ctypes test_fcntl test_math test_regrtest test_shutil test_strptime test_winreg test_wsgiref
      • py_compile: test_cmd_line_script test_importlib test_modulefinder test_multiprocessing_main_handling test_py_compile test_runpy
      • random: test_asyncio test_bisect test_complex test_context test_dbm_dumb test_devpoll test_dummy_thread test_email test_float test_grp test_heapq test_hmac test_importlib test_int test_long test_mmap test_numeric_tower test_poll test_pow test_pprint test_pwd test_queue test_richcmp test_selectors test_sort test_strtod test_struct test_sys test_thread test_threading test_tokenize test_zipfile test_zstd
      • sqlite3.main: test_sqlite3
      • tokenize: test_linecache test_tabnanny
      • webbrowser: test_webbrowser
      • zipapp: test_zipapp
      • zipfile: test_pkgutil test_zipfile test_zipfile64
    • collections: test_asyncio test_c_locale_coercion test_call test_contains test_embed test_exception_group test_file test_fileio test_funcattrs test_hash test_iterlen test_json test_pathlib test_reprlib test_sqlite3 test_urllib test_userdict test_userlist test_userstring test_with
      • concurrent.futures._base: test_concurrent_futures
      • dbm.sqlite3: test_dbm_sqlite3
      • difflib: test_difflib test_profile test_sys_settrace
      • idlelib: test_idle
      • importlib.metadata: test_importlib
      • logging: test_asyncio test_hashlib test_support test_urllib2net
      • multiprocessing: test_asyncio test_concurrent_futures
      • pkgutil: test_pyrepl
      • pprint: test_htmlparser test_sys_setprofile
      • queue: test_android test_concurrent_futures test_sched
      • selectors: test_asyncio test_subprocess
      • shlex: test_shlex
      • shutil: test_ctypes test_filecmp test_glob test_largefile test_launcher test_peg_generator test_sax test_string_literals test_tempfile test_unicode_file
      • ssl: test_ftplib test_httplib test_poplib
      • string: test_email test_fnmatch test_importlib test_pyrepl test_secrets test_string
      • threading: test_asyncio test_concurrent_futures test_contextlib test_ctypes test_docxmlrpc test_external_inspection test_fork1 test_gc test_importlib test_ioctl test_pathlib test_pyrepl test_smtplib test_socketserver test_syslog test_termios test_threadedtempfile test_threading_local
      • traceback: test_asyncio test_code_module test_contextlib_async test_dictcomps test_http_cookiejar test_importlib test_listcomps test_pyexpat test_setcomps test_unittest
      • tracemalloc: test_tracemalloc
      • urllib.parse: test_urllibnet test_urlparse
      • wave: test_wave
      • xml.etree.ElementTree: test_doctest
    • dataclasses: test__colorize test_ctypes
      • pstats: test_pstats
    • email.generator: test_email
      • mailbox: test_mailbox
      • smtplib: test_smtpnet
    • gettext: test_gettext test_tools
      • getopt: test_getopt
    • weakref: test_asyncio test_ctypes test_finalization test_scope test_sqlite3 test_unicodedata test_unittest
      • bdb: test_bdb
      • symtable: test_symtable
      • tempfile: test_cmd_line test_cprofile test_faulthandler test_generated_cases test_importlib test_pkg test_pyrepl test_urllib_response test_winconsoleio

[x] lib: cpython/Lib/collections
[ ] lib: cpython/Lib/_collections_abc.py
[x] test: cpython/Lib/test/test_collections.py
[x] test: cpython/Lib/test/test_deque.py (TODO: 1)
[x] test: cpython/Lib/test/test_defaultdict.py
[x] test: cpython/Lib/test/test_ordered_dict.py

dependencies:

  • collections (native: _collections, _weakref, itertools, sys)
    • _collections_abc
    • _collections_abc (native: sys)
    • warnings (native: _contextvars, _thread, _warnings, builtins, sys)
    • copy
    • abc, annotationlib, heapq, keyword, operator, reprlib

dependent tests: (334 tests)

  • collections: test_annotationlib test_array test_asyncio test_bisect test_builtin test_c_locale_coercion test_call test_collections test_configparser test_contains test_context test_copy test_csv test_ctypes test_defaultdict test_deque test_descr test_dict test_dictviews test_embed test_enum test_exception_group test_file test_fileinput test_fileio test_frame test_funcattrs test_functools test_genericalias test_hash test_httpservers test_inspect test_io test_ipaddress test_iter test_iterlen test_json test_logging test_math test_monitoring test_ordered_dict test_pathlib test_patma test_pickle test_plistlib test_pprint test_pydoc test_random test_reprlib test_richcmp test_set test_shelve test_sqlite3 test_statistics test_string test_struct test_sys test_traceback test_tuple test_types test_typing test_unittest test_urllib test_userdict test_userlist test_userstring test_weakref test_weakset test_with
    • ast: test_ast test_codeop test_compile test_compiler_codegen test_dis test_fstring test_future_stmt test_peepholer test_peg_generator test_site test_ssl test_type_comments test_ucn test_unparse
      • annotationlib: test_grammar test_type_annotations test_type_params
      • dbm.dumb: test_dbm_dumb
      • inspect: test_abc test_argparse test_asyncgen test_buffer test_clinic test_code test_coroutines test_decimal test_generators test_ntpath test_operator test_posixpath test_signal test_turtle test_yield_from test_zipimport test_zipimport_support test_zoneinfo
      • pyclbr: test_pyclbr
      • traceback: test_asyncio test_code_module test_contextlib test_contextlib_async test_dictcomps test_exceptions test_http_cookiejar test_importlib test_listcomps test_pyexpat test_setcomps test_socket test_subprocess test_threadedtempfile test_threading test_unittest
    • asyncio: test_asyncio test_concurrent_futures test_external_inspection test_os test_pdb
    • concurrent.futures._base: test_concurrent_futures
    • dbm.sqlite3: test_dbm_sqlite3
    • difflib: test_difflib test_profile test_sys_settrace
    • dis: test__opcode test_compiler_assemble test_dtrace test_opcache test_positional_only_arg test_type_cache
      • bdb: test_bdb
      • modulefinder: test_importlib test_modulefinder
      • trace: test_trace
    • email.feedparser: test_email
    • http.client: test_docxmlrpc test_hashlib test_unicodedata test_urllib2 test_wsgiref test_xmlrpc
      • urllib.request: test_sax test_urllib2_localnet test_urllib2net test_urllibnet
    • idlelib: test_idle
    • importlib.metadata: test_importlib
    • inspect:
      • cmd: test_cmd
      • dataclasses: test__colorize test_ctypes test_regrtest
      • pkgutil: test_pkgutil test_pyrepl test_runpy
      • rlcompleter: test_pyrepl test_rlcompleter
    • logging: test_support
      • hashlib: test_hmac test_smtplib test_tarfile
      • multiprocessing.util: test_compileall test_concurrent_futures
      • venv: test_venv
    • multiprocessing: test_fcntl test_memoryview test_multiprocessing_main_handling test_re
    • platform: test__locale test__osx_support test_baseexception test_cmath test_ctypes test_mimetypes test_platform test_posix test_shutil test_strptime test_sysconfig test_time test_winreg
    • pprint: test_htmlparser test_sys_setprofile
      • pickle: test_bool test_bytes test_bz2 test_codecs test_concurrent_futures test_ctypes test_email test_enumerate test_fractions test_http_cookies test_itertools test_list test_lzma test_memoryio test_minidom test_picklebuffer test_pickletools test_range test_slice test_str test_structseq test_super test_type_aliases test_unittest test_uuid test_xml_dom_minicompat test_xml_etree test_xpickle test_zipfile test_zlib test_zoneinfo
    • queue: test_android test_concurrent_futures test_dummy_thread test_sched
    • selectors: test_selectors
      • socket: test_epoll test_exception_hierarchy test_ftplib test_httplib test_imaplib test_kqueue test_largefile test_mailbox test_mmap test_poplib test_pty test_smtpnet test_socketserver test_stat test_timeout test_urllib_response
      • subprocess: test_atexit test_audit test_cmd_line test_cmd_line_script test_ctypes test_faulthandler test_file_eintr test_gc test_gzip test_json test_launcher test_msvcrt test_osx_env test_peg_generator test_poll test_py_compile test_pyrepl test_quopri test_repl test_script_helper test_select test_tempfile test_unittest test_utf8_mode test_wait3 test_webbrowser test_zipfile
    • shlex: test_shlex
    • shutil: test_filecmp test_glob test_importlib test_string_literals test_unicode_file
      • ctypes.util: test_ctypes
      • ensurepip: test_ensurepip
      • pathlib: test_importlib test_pathlib test_tomllib test_tools test_winapi test_zipapp test_zstd
      • tempfile: test_cprofile test_doctest test_generated_cases test_importlib test_linecache test_pkg test_pstats test_pyrepl test_tabnanny test_termios test_tokenize test_winconsoleio test_zipfile64
      • zipfile: test_zipfile
    • statistics:
      • random: test_complex test_devpoll test_email test_float test_grp test_heapq test_int test_long test_numeric_tower test_pow test_pwd test_queue test_sort test_strtod test_thread
    • string: test_email test_fnmatch test_pyrepl test_secrets test_string
    • threading: test_concurrent_futures test_ctypes test_fork1 test_importlib test_ioctl test_pyrepl test_robotparser test_syslog test_threading_local
      • dummy_threading: test_dummy_threading
      • sysconfig: test_asdl_parser test_tools
    • traceback:
      • timeit: test_timeit
    • tracemalloc: test_tracemalloc
    • urllib.parse: test_urlparse
    • wave: test_wave

Legend:

  • [+] path exists in CPython
  • [x] up-to-date, [ ] outdated

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