PyPy v7.3.22: release of python 2.7, 3.11, released 2026-04-26

The PyPy team is proud to release version 7.3.22 of PyPy after the previous release on March 13, 2026. This is a bug-fix release that fixes several issues in the JIT. Among them, a long-standing JIT bug that started appearing when some instance optimizations exposed it. We also cleaned up many of the remaining stdlib test suite failures, which improves CPython compatibility around line numbers in dis.dis, signatures and objclass attributes for builtins, and other quality of life features.

There is now an RPython _pickle module that mirrors the CPython one, greatly speeding up pickling operations. Where before PyPy was 5.7x slower than CPython on the pickle benchmark from the pyperformance benchmark suite, now it is only 1.6x slower [0]. We also added pypy pickler extensions to dump and load lists using list strategies, and enabled them in the ForkingPickler used by multiprocessing, speeding up cases where such objects are passed between PyPy multiprocessing instances.

We also added an RPython json encoder, speeding up json_bench from being 2.6x slower than CPython to being 0.7x (meaning faster).

The release includes two different interpreters:

  • PyPy2.7, which is an interpreter supporting the syntax and the features of Python 2.7 including the stdlib for CPython 2.7.18+ (the + is for backported security updates)
  • PyPy3.11, which is an interpreter supporting the syntax and the features of Python 3.11, including the stdlib for CPython 3.11.15.

The interpreters are based on much the same codebase, thus the double release. This is a micro release, all APIs are compatible with the other 7.3 releases.

We recommend updating. You can find links to download the releases here:

We would like to thank our donors for the continued support of the PyPy project. If PyPy is not quite good enough for your needs, we are available for direct consulting work. If PyPy is helping you out, we would love to hear about it and encourage submissions to our blog via a pull request to https://github.com/pypy/pypy.org

We would also like to thank our contributors and encourage new people to join the project. PyPy has many layers and we need help with all of them: bug fixes, PyPy and RPython documentation improvements, or general help with making RPython’s JIT even better.

If you are a python library maintainer and use C-extensions, please consider making a HPy / CFFI / cppyy version of your library that would be performant on PyPy. In any case, cibuildwheel supports building wheels for PyPy.

Footnotes

[0]Once a PR to pyperformance to use the _pickle module on PyPy is accepted

What is PyPy?

PyPy is a Python interpreter, a drop-in replacement for CPython. It’s fast (PyPy and CPython performance comparison) due to its integrated tracing JIT compiler.

We also welcome developers of other dynamic languages to see what RPython can do for them.

We provide binary builds for:

  • x86 machines on most common operating systems (Linux 32/64 bits, Mac OS 64 bits, Windows 64 bits)
  • 64-bit ARM machines running Linux (aarch64) and macos (macos_arm64).

PyPy supports Windows 32-bit, Linux PPC64 big- and little-endian, Linux ARM 32 bit, RISC-V RV64IMAFD Linux, and s390x Linux but does not release binaries. Please reach out to us if you wish to sponsor binary releases for those platforms. Downstream packagers provide binary builds for debian, Fedora, conda, OpenBSD, FreeBSD, Gentoo, and more.

Changelog

For all versions

Bugfixes

  • Fix instance dictionary field reordering logic, which could lead to a failing internal assertion error under some circumstances (#5377).
  • Fix JIT invalidation logic of array items at a variable index, which could lead to incorrect results for list accesses when also calling methods on list objects (#5389)
  • Fix segfaults in the JIT where the JIT optimizer would confuse RPython instances and arrays, leading to segfaults during JIT compilation (#5400).
  • Fix duplicate ‘const’ in C code generation for nested const pointer types

Speedups and enhancements

  • Improve the performance of left-shifts of large integers, ie those backed by RPython’s rbigints (#5404).
  • Fix ~10ms GIL wakeup latency on Windows (#5391)
  • Improve performance of complex powers with small integers as exponents
  • Document the fact that in PyPy instance dictionaries are not always ordered by insertion (#5436).

Python 2.7

  • Remove unsafe pickle file handling from bundled ply in pycparser v2. PyPy3 uses pycparser v3

Python 3.11

  • Cherry-pick upstream _pydecimal fix from CPython (#5256).
  • Add sys._stdlib_dir
  • Disallow whitespace after sign character in int/float string parsing (#3927)

Bugfixes including missing compatibility with CPython 3.11

  • Make itertools.pairwise reentrant (python/cpython#109788)
  • Fix possessive repeat in rsre search and match, fixing possessive regex bugs
  • Fix crash in the bytecode compiler related to the line numbers of return statements (#5419).
  • Fixed line number output for function definitions with multiple decorators, f-strings, and related edge cases in dis output
  • Fixed pyrepl and pdb compatibility
  • cpyext: fix exposing __self__ attribute on cpyext methods (#5368)
  • cpyext: fix getsetdescr_attach to avoid redundantly rebuilding descriptors (#5402)
  • cpyext: when checking for tp_new, ignore object.__new__ (#5418)
  • cpyext: fix flag propagation via inheritance and add flags to type objects
  • cpyext: fix tp_basicsize computation for mixed python/c-extension MRO types (#5402)
  • cpyext: fix type layouts for types with tp_dictoffset or tp_weaklistoffset (#5402)
  • cpyext: fix PyGC_Collect to better mimic a full collection cycle
  • Fix TextIOWrapper.readline(None) (#5379)
  • Fix PREP_RERAISE_STAR dropping the current traceback (#5338)
  • Fix missing case in astcompiler for multiple trinary expressions (#5419)
  • Fix function.__get__(None) to raise TypeError like CPython
  • Fix multiple decorators raising exceptions in reverse order (#5213)
  • Fix normalize_exception when called inside generators
  • Fix edge cases in generator and coroutine execution
  • Fix raise ignoring user modifications to __traceback__
  • Fix segfault in Parser.diagnose() called after a successful parse
  • Fix error message for empty f-strings
  • Fix error messages for range() argument parsing
  • Fix edge cases in __future__ handling and eval
  • Fix unparse edge cases: lambda positional-only args, await in annotations
  • Fix multiline UTF-8 error messages
  • Fix encoding failures in _tkinter
  • Fix various ctypes edge cases
  • Fix hpy debug mode failures
  • signal: handle failed wakeup-fd so it can be polled
  • Add more check_valid() calls to mmap
  • Raise SyntaxError for unterminated single-quoted strings ending in newline in the REPL
  • Fix missing __reduce__ on cpyext methods, exposed by _pickle (#5445)
  • Fix signatures of some math functions (#5368)
  • Add __doc__ and __text_signature__ to more cpyext types (#5368)

Speedups and enhancements

  • pyrepl: implement set_completion_display_matches_hook, parse_and_bind, and set_pre_input_hook
  • Generate default docstring from __text_signature__ at interp2app
  • Emit ($self ...) for method signatures, used by inspect
  • Make the first build of lib_pypy cffi modules quieter (#5428)
  • Implement shared tuples in app-level marshal
  • Speed up the cffi implementation of the fast path for hashlib.new(name, data).hexdigest()
  • Speed up the sqlitesynth benchmark in _cffi_sqlite3