# PyPy2.7 v5.3

We have released PyPy2.7 v5.3, about six weeks after PyPy 5.1 and a week after PyPy3.3 v5.2 alpha 1, the first PyPy release targeting 3.3 compatibility. This new PyPy2.7 release includes further improvements for the CAPI compatibility layer which we call cpyext. In addition to complete support for lxml, we now pass most (more than 90%) of the upstream numpy test suite, and much of SciPy is supported as well.

We updated cffi to version 1.7 (small changes, documented here).

You can download the PyPy2.7 v5.3 release here:

> https://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. 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.

This 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

## Other Highlights (since 5.1 released in April 2016)

- New features:

  - Merge a major expansion of the C-API support in cpyext, here are some of the highlights:

    > - allow c-snippet tests to be run with -A so we can verify we are compatible

    > - fix many edge cases exposed by fixing tests to run with -A

    > - issequence() logic matches cpython

    > - make PyStringObject and PyUnicodeObject field names compatible with cpython

    > - add prelminary support for PyDateTime_*

    > - support PyComplexObject, PyFloatObject, PyDict_Merge, PyDictProxy, PyMemoryView_*, _Py_HashDouble, PyFile_AsFile, PyFile_FromFile, PyAnySet_CheckExact, PyUnicode_Concat, PyDateTime_TZInfo

    > - improve support for PyGILState_Ensure, PyGILState_Release, and thread primitives, also find a case where CPython will allow thread creation before PyEval_InitThreads is run, disallow on PyPy

    > - create a PyObject-specific list strategy

    > - rewrite slot assignment for typeobjects

    > - improve tracking of PyObject to rpython object mapping

    > - support tp_as_{number, sequence, mapping, buffer} slots

    > - support ByteArrayObject via the new resizable_list_supporting_raw_ptr

    > - implement PyList_SET_ITEM with CPython's behavior, instead of SetItem's

    > - fix the signature of PyUFunc_FromFuncAndDataAndSignature

    > - implement many PyWhatever_FOO() as a macro taking a void *

  - CPyExt tweak: instead of "GIL not held when a CPython C extension module calls PyXxx", we now silently acquire/release the GIL. Helps with CPython C extension modules that call some PyXxx() functions without holding the GIL (arguably, they are theoretically buggy).

  - Add rgc.FinalizerQueue, documented in pypy/doc/discussion/finalizer-order.rst. It is a more flexible way to make RPython finalizers. Use this mechanism to clean up handling of `__del__` methods, fixing issue #2287

  - Generalize cpyext old-style buffers to more than just str/buffer, add support for mmap

  - Support command line -v to trace import statements

  - Add rposix functions for PyPy3.3 support

  - Give super an __init__ and a simple __new__ for CPython compatibility

  - Revive traceviewer, a tool to use pygame to view traces

- Bug Fixes

  - Fix issue #2277: only special-case two exact lists in zip(), not list subclasses, because an overridden __iter__() should be called (probably)

  - Fix issue #2226: Another tweak in the incremental GC- this should ensure that progress in the major GC occurs quickly enough in all cases.

  - Clarify and refactor documentation on https://doc.pypy.org

  - Use "must be unicode, not %T" in unicodedata TypeErrors.

  - Manually reset sys.settrace() and sys.setprofile() when we're done running. This is not exactly what CPython does, but if we get an exception, unlike CPython, we call functions from the 'traceback' module, and these would call more the trace/profile function. That's unexpected and can lead to more crashes at this point.

  - Use the appropriate tp_dealloc on a subclass of a builtin type, and call tp_new for a python-sublcass of a C-API type

  - Fix for issue #2285 - rare vmprof segfaults on OS/X

  - Fixed issue #2172 - where a test specified an invalid parameter to mmap on powerpc

  - Fix issue #2311 - grab the __future__ flags imported in the main script, in -c, or in PYTHON_STARTUP, and expose them to the -i console

  - Issues reported with our previous release were resolved after reports from users on our issue tracker at https://bitbucket.org/pypy/pypy/issues or on IRC at #pypy

- Numpy:

  - Implement ufunc.outer on numpypy

  - Move PyPy-specific numpy headers to a subdirectory (also changed the repo accordingly)

- Performance improvements:

  - Use bitstrings to compress lists of descriptors that are attached to an EffectInfo

  - Remove most of the _ovf, _zer and _val operations from RPython. Kills quite some code internally, and allows the JIT to do better optimizations: for example, app-level code like `x / 2` or `x % 2` can now be turned into `x >> 1` or `x & 1`, even if x is possibly negative.

  - Copy CPython's 'optimization': ignore __iter__ etc. for f(**dict_subclass())

  - Use the __builtin_add_overflow built-ins if they are available

  - Rework the way registers are moved/spilled in before_call()

- Internal refactorings:

  - Refactor code to better support Python3-compatible syntax

  - Document and refactor OperationError -> oefmt

  - Reduce the size of generated C sources during translation by eliminating many many unused struct declarations (Issue #2281)

  - Remove a number of translation-time options that were not tested and never used. Also fix a performance bug in the method cache

  - Reduce the size of generated code by using the same function objects in all generated subclasses

  - Share cpyext Py* function wrappers according to the signature, shrinking the translated libpypy.so by about 10% (measured without the JIT)

  - Compile c snippets with -Werror, and fix warnings it exposed

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

Cheers

The PyPy Team