PyPy v7.3.12: release of python 2.7, 3.9, and 3.10

The PyPy team is proud to release version 7.3.12 of PyPy. This release includes a new string-to-int algorithm (also appearing in CPython 3.12) that is faster than the older one; support for symlinks in Windows; and our first Python3.10 version.

The release includes three 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)
  • PyPy3.9, which is an interpreter supporting the syntax and the features of Python 3.9, including the stdlib for CPython 3.9.17.
  • PyPy3.10, which is an interpreter supporting the syntax and the features of Python 3.10, including the stdlib for CPython 3.10.12. This is our first release of 3.10, but based on past experience we are quite confident in its compatibility with upstream. Of course, we recommend testing your code with this new version before putting it into production. Note it does require at least cython 0.29.35 or cython 3.0.0b3

The interpreters are based on much the same codebase, thus the multiple release. This is a micro release, all APIs are compatible with the other 7.3 releases. It follows after 7.3.11 release on Dec 29, 2022

We recommend updating. You can find links to download the v7.3.12 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

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. Since the previous release, we have accepted contributions from one new contributor, thanks for pitching in, and welcome to the project!

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, both cibuildwheel and the multibuild system support building wheels for PyPy.

What is PyPy?

PyPy is a Python interpreter, a drop-in replacement for CPython It’s fast (PyPy and CPython 3.7.4 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).
  • Apple M1 arm64 machines (macos_arm64).
  • s390x running Linux

PyPy support Windows 32-bit, Linux PPC64 big- and little-endian, and Linux ARM 32 bit, 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.


For all versions

  • Update vendored version of pycparser
  • Update to ssl 1.1.1u, 3.0.9; lzma 5.2.10; and gdbm 1.23 when embedding libraries for a portable build


  • Allow creating ctypes.py_object() on a weakref (issue 3883)
  • Add memory pressure for malloc allocations in _ssl, fix OpenSSL context use
  • Pair OpenSSL allocation calls better with free calls in _ssl (issue 3887)
  • Only define SO in sysconfig if imp.get_suffixes() has imp.C_EXTENSION
  • Fix wrong assert in intutils, it should be an InvalidLoop instead (issue 3892:_)
  • export PyDescr_NewGetSet and define PyDescr_TYPE, PyDescr_NAME
  • space.index(W_Bool) should return an int, not a bool (issue 3906)
  • Skip cpython pickling of range
  • Support loading c-extension modules with both powerpc64le-linux-gnu and ppc_64-linux-gnu platform tags (issue 3834)
  • Fix various cases where a mutating __index__ method could crash the interpreter (issue 3917)
  • Use C99 NAN for Py_NAN

Speedups and enhancements

  • Do less string copies in the bytecode compiler
  • Add missing CJK range in unicodedata version 13
  • Implement the base 10 string-to-int conversion using a divide an conquer algorithm with complexity O(n**1.58). The algorithm is due to Bjorn Martinsson and is part of CPython 3.12.
  • Small refactoring in the JIT History class. It can now use the proper opencoder encoding of a trace immediately, not only after the inputargs are known
  • Inline get_field_updater in JITted code to allow FieldUpdater to be alloc-removed everywhere
  • Improve warmup a little bit: - directly put the two most common opcodes into the loop - add a special case for the int_add variant with a constant argument
  • Use the rbigint.add_int (etc) shortcuts for the int+int overflowing operations
  • Optimize the goto_if_not_* code: - don’t call replace_box for fresh boxes that can’t be stored anywhere yet - make the “same box” shortcut faster

Python 3.9+


  • Fix corner case when computing __main__.__file__ (issue 3881)
  • Fix misnamed function (issue 3874)
  • Disallow pickle of staticmethod, classmethod, and DirEntry
  • Make sure that the max stackdepth is observed in method calls
  • Fix utf-16 and utf-32 errorhandler replacement logic: if the replacement is bytes. those are just copied to the output
  • Fix the problems of
  • Fix str_decode_raw_unicode_escape for the case of \\, which was incorrectly special-cased.
  • Forbid null bytes in pwd.getpwnam
  • Use r_longlong math in nanosecond time for perf_counter on windows (issue 3890)
  • Fix for tuple.contains(obj) using item == obj (bpo-37648)
  • Allow indexing with a class with a __index__ method
  • Implement __copy__ and __deepcopy__ for zlib (de)compressors
  • Fix weirdness about combining annotations and a global declaration of a name in some random function (issue 3925)
  • Fix wrong implementation of _copy_base for slices of n-dimensional buffers (issue 3520)
  • Trim the scope ID from IPV6 addresses (issue 3938, reversing the decision in issue 3628)
  • Add _hashlib.scrypt (issue 3921)
  • Properly create a C-level wrapper that calls tp_finalize when __del__ is called, which allows us to use CYTHON_USE_TP_FINALIZE in cython
  • Move hpy.dist-info to hpy-0.0.4.dist-info (issue 3579)
  • Fix edged cases in __rpow__ and pow() (issues 3912 and 3944)
  • Remove PyInt_FromLong which was leftover from Python2

Speedups and enhancements

  • Speed up nametuple _replace by code generation (issue 3884)
  • Correct exception on positional arguments, while supporting empty namedtuple (?) at the same time
  • Implement os.symlink and os.readlink on windows
  • Fix os.mkdir for unicode handling via teaching rposix about utf-8 paths, which could lead to removing the last vestiges of unicode from rpython.
  • Refactor os.remove/os.unlink to take symlink into account on windows
  • Increment macosx-version-min to 10.9
  • space.newlong returns a W_LongObject on pypy3, where there is no observable applevel difference between W_IntObject and W_LongObject
  • Provide _PyEval_GetAsyncGenFirstiter and _PyEval_GetAsyncGenFinalizer for use by cython, towards fixing issue 3280
  • Squeeze a little more accuracy out of windows time.time(), to make a cython test pass
  • Use posonly args for list.__init__ and set.__init__, simplifying code
  • Use rbigint.*_int fast paths for comparisons between ints