# PyPy2.7 and PyPy3.5 v5.7 - two in one release

The PyPy team is proud to release both PyPy2.7 v5.7 (an interpreter supporting Python v2.7 syntax), and a beta-quality PyPy3.5 v5.7 (an interpreter for Python v3.5 syntax). The two releases are both based on much the same codebase, thus the dual release. Note that PyPy3.5 supports Linux 64bit only for now.

This new PyPy2.7 release includes the upstream stdlib version 2.7.13, and PyPy3.5 (our first in the 3.5 series) includes the upstream stdlib version 3.5.3.

We continue to make incremental improvements to our C-API compatibility layer (cpyext). PyPy2 can now import and run many C-extension packages, among the most notable are Numpy, Cython, and Pandas. Performance may be slower than CPython, especially for frequently-called short C functions. Please let us know if your use case is slow, we have ideas how to make things faster but need real-world examples (not micro-benchmarks) of problematic code.

Work proceeds at a good pace on the PyPy3.5 version due to a grant from the Mozilla Foundation, hence our first 3.5.3 beta release. Thanks Mozilla !!! While we do not pass all tests yet, asyncio works and as these benchmarks show it already gives a nice speed bump. We also backported the `f""` formatting from 3.6 (as an exception; otherwise "PyPy3.5" supports the Python 3.5 language).

CFFI has been updated to 1.10, improving an already great package for interfacing with C.

We now use shadowstack as our default gcrootfinder even on Linux. The alternative, asmgcc, will be deprecated at some future point. While about 3% slower, shadowstack is much more easily maintained and debuggable. Also, the performance of shadowstack has been improved in general: this should close the speed gap between Linux and other platforms.

As always, this release fixed many issues and bugs raised by the growing community of PyPy users. We strongly recommend updating.

You can download the v5.7 release here:

> http://pypy.org/download.html

We would like to thank our donors for the continued support of the PyPy project.

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: PyPy and RPython documentation improvements, tweaking popular modules to run on pypy, or general help with making RPython's JIT even better.

## What is PyPy?

PyPy is a very compliant Python interpreter, almost a drop-in replacement for CPython 2.7 and CPython 3.5. It's fast (PyPy and CPython 2.7.x 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.

The PyPy 2.7 release supports:

> - x86 machines on most common operating systems (Linux 32/64 bits, Mac OS X 64 bits, Windows 32 bits, OpenBSD, FreeBSD)
> - newer ARM hardware (ARMv6 or ARMv7, with VFPv3) running Linux,
> - big- and little-endian variants of PPC64 running Linux,
> - s390x running Linux

## Highlights of the PyPy2.7, cpyext, and RPython changes (since 5.6 released Nov, 2016)

See also issues that were resolved

- New features and cleanups
  - update the format of the PYPYLOG file and improvements to vmprof
  - emit more sysconfig values for downstream cextension packages including properly setting purelib and platlib to site-packages
  - add `PyAnySet_Check`, `PyModule_GetName`, `PyWeakref_Check*`, `_PyImport_{Acquire,Release}Lock`, `PyGen_Check*`, `PyOS_AfterFork`,
  - detect and raise on recreation of a PyPy object from a PyObject during tp_dealloc
  - refactor and clean up poor handling of unicode exposed in work on py3.5
  - builtin module cppyy supports C++ 11, 14, etc. via cling (reflex has been removed)
  - adapt `weakref` according to CPython issue 19542, will be in CPython 2.7.14
  - support translations with cpyext and the Boehm GC (for special cases like RevDB
  - implement `StringBuffer.get_raw_address` for the buffer protocol, it is now possible to obtain the address of any readonly object without pinning it
  - refactor the initialization code in translating cpyext
  - use a cffi-style C parser to create rffi objects in cpyext, now the translating Python must have either `cffi` or `pycparser` available
  - implement `move_to_end(last=True/False)` on RPython ordered dicts, make available as `__pypy__.move_to_end` and, on py3.5, `OrderedDict.move_to_end()`
  - remove completely RPython `space.wrap` in a major cleanup, differentiate between `space.newtext` and `space.newbytes` on py3.5
  - any uncaught RPython exception in the interpreter is turned into a SystemError (rather than a segfault)
  - add translation time --disable_entrypoints option for embedding PyPy together with another RPython VM
- Bug Fixes
  - fix `"".replace("", "x", num)` to give the same result as CPython
  - create log files without the executable bit
  - disable `clock_gettime()` on OS/X, since we support 10.11 and it was only added in 10.12
  - support `HAVE_FSTATVFS` which was unintentionally always false
  - fix user-created C-API heaptype, issue 2434
  - fix `PyDict_Update` is not actually the same as `dict.update`
  - assign `tp_doc` on `PyTypeObject` and tie it to the app-level `__doc__` attribute issue 2446
  - clean up memory leaks around `PyObject_GetBuffer`, `PyMemoryView_GET_BUFFER`, `PyMemoryView_FromBuffer`, and `PyBuffer_Release`
  - improve support for creating C-extension objects from app-level classes, filling more slots, especially `tp_new` and `tp_dealloc`
  - fix for `ctypes.c_bool` returning `bool` restype, issue 2475
  - fix in corner cases with the GIL and C-API functions
  - allow overriding thread.local.__init__ in a subclass, issue 2501
  - allow `PyClass_New` to be called with NULL as the first arguemnt, issue 2504
- Performance improvements:
  - clean-ups in the jit optimizeopt
  - optimize `if x is not None: return x` or `if x != 0: return x`
  - add `jit.conditional_call_elidable()`, a way to tell the JIT "conditonally call this function" returning a result
  - try harder to propagate `can_be_None=False` information
  - add `rarithmetic.ovfcheck_int32_add/sub/mul`
  - add and use `rgc.may_ignore_finalizer()`: an optimization hint that makes the GC stop tracking the object
  - replace malloc+memset with a single calloc, useful for large allocations?
  - linux: try to implement os.urandom() as the syscall getrandom() if available
  - propagate `debug.ll_assert_not_none()` through the JIT to reduce number of guards
  - improve the performance of `PyDict_Next`
  - improve `dict.pop()`
  - improve the optimization of branchy Python code by retaining more information across failing guards
  - add optimized "zero-copy" path for `io.FileIO.readinto`
- RPython improvements
  - improve the consistency of RPython annotation unions
  - add translation option --keepgoing to continue after the first AnnotationError
  - improve shadowstack to where it is now the default in place of asmgcc
  - add a rpython implementation of siphash24, allow choosing hash algorithm randomizing the seed
  - add rstack.stack_almost_full() and use it to avoid stack overflow due to the JIT where possible

## Highlights of the PyPy3.5 release (since 5.5 alpha released Oct, 2016)

Development moved from the py3k branch to the py3.5 branch in the PyPy bitbucket repo.

- New features
  - this first PyPy3.5 release implements most of Python 3.5.3, exceptions are listed below
  - PEP 456 allowing secure and interchangable hash algorithms
  - use cryptography's cffi backend for SSL
- Bug Fixes
  - implement fixes for some CPython issues that arose since the last release
  - solve deadlocks in thread locking mechanism
- Performance improvements:
  - do not create a list whenever `descr_new` of a `bytesobject` is called
- The following features of Python 3.5 are not implemented yet in PyPy:
  - PEP 442: Safe object finalization
  - PEP 489: Multi-phase extension module initialization

Please update, and continue to help us make PyPy better.

Cheers