PyPy v7.3.16: release of python 2.7, 3.9, and 3.10

The PyPy team is proud to release version 7.3.16 of PyPy.

This release includes security fixes from upstream CPython, and bugfixes to the garbage collector, described in a gc bug-hunt blog post.

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 3.9.19.
  • PyPy3.10, which is an interpreter supporting the syntax and the features of Python 3.10, including the stdlib for CPython 3.10.14.

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 7.3.15 release on Jan 15, 2024

We recommend updating. You can find links to download the v7.3.16 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.

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

  • Make some RPython code Python3 compatible, including supporting print()
  • Make test_transformed_gc tests more stable
  • Document the %d feature in PYPYLOG env var file name
  • Update vendored pycparser for its 2.22 release
  • Raise default gc nursery size to 4MB (#4939)


  • Fix the action dispatcher in garbage collector hooks (#4899)
  • Fix 'const' in signature of gdbm_open (#4926)
  • Fix garbage collector incminimark arraycopy incrementality bug (#4925, #3959)
  • Fix pinning/shadow interaction bugs in the incminimark GC (#4900)

Speedups and enhancements

  • Move uint_mul_high to rarithmetic and add support for it in the metainterp
  • Add a setattr shortcut to StdObjspace like the existing getattr, and implement a STOR_ATTR optimization, and extend it to work for adding attributes as well.
  • Update CFFI to 1.17.0dev0
  • Constant-fold typeptr getfields
  • Update to stdlib 3.9.19 including changes to _ssl and vendoring expat into the repo
  • Implement dict.__ror__ (#4934)

Python 3.9+


  • _putwch on windows accepts a chr not an int (#4881)
  • Properly create ppc64 import suffixes for c-extensions (:issue:`
  • Backport cpython fix to prevent subclassing datetime.timezone (python/cpython#112453)
  • Remove top level from stdlib (#4885)
  • Replace handshake_done with SSL_is_init_finished (bpo-29334 from CPython3.5)
  • Fix some subtle _ssl incompatibilities in error handling (#4883)
  • Port cffi change to better parse repetitive pragmas (#python-cffi/cffi#46)
  • Port cffi change to better parse complex number semantics on windows (#python-cffi/cffi#57)
  • Set tp_doc when defined in PyGetSetDef (#4898)
  • Use Py_UCS4 not PY_UNICODE in various PyUnicode function input (#4901)
  • Make str.expandtabs() do the right thing with unicode characters and speed it up (#4920)
  • Fix 'const' in signature of Tcl_Merge (#4926)
  • Close connection to avoid resource leak in multiprocessing.managers
  • Fix str.__mul__(str) to raise rather than return NotImplemented
  • Sync pure-python with upstream CPython3.13 to match C _stat implementation of filemode

Speedups and enhancements

  • Add PyModule_GetFilenameObject and PyModule_GetNameObject
  • Speed up normalize_exception by reduced copying
  • Update xz-utils to 5.4.6 when building _lzma
  • Add sys._git

Python 3.10


  • Make stack depth computation more precise. Stack depths of various instructions were off by one for historical reasons. The errors carefully balanced each other out. Now code that does exception handling has smaller maximum stack sizes.