PyPy 1.1 final released!

Carl Friedrich Bolz cfbolz at
Tue Apr 28 16:55:29 CEST 2009

PyPy 1.1: Compatibility & Consolidation

Welcome to the PyPy 1.1 release - the first release after the end of EU
funding. This release focuses on making PyPy's Python interpreter more
compatible with CPython (currently CPython 2.5) and on making the
interpreter more stable and bug-free.

PyPy's Getting Started lives at:

Highlights of This Release

   - More of CPython's standard library extension modules are supported,
     among them ctypes, sqlite3, csv, and many more. Most of these extension
     modules are fully supported under Windows as well.

   - Through a large number of tweaks, performance has been improved by
     10%-50% since the 1.0 release. The Python interpreter is now between
     0.8-2x (and in some corner case 3-4x) slower than CPython. A large
     part of these speed-ups come from our new generational garbage

   - Our Python interpreter now supports distutils as well as
     easy_install for pure-Python modules.

   - We have tested PyPy with a number of third-party libraries. PyPy can
     run now: Django, Pylons, BitTorrent, Twisted, SymPy, Pyglet, Nevow,

   - A buildbot was set up to run the various tests that PyPy is using
     nightly on Windows and Linux machines:

   - Sandboxing support: It is possible to translate the Python
     interpreter in a special way so that the result is fully sandboxed.

Other Changes

   - The ``clr`` module was greatly improved. This module is used to
     interface with .NET libraries when translating the Python
     interpreter to the CLI.

   - Stackless improvements: PyPy's ``stackless`` module is now more
     complete. We added channel preferences which change details of the
     scheduling semantics. In addition, the pickling of tasklets has been
     improved to work in more cases.

   - Classic classes are enabled by default now. In addition, they have
     been greatly optimized and debugged:

   - PyPy's Python interpreter can be translated to Java bytecode now to
     produce a pypy-jvm. At the moment there is no integration with
     Java libraries yet, so this is not really useful.

   - We added cross-compilation machinery to our translation toolchain to
     make it possible to cross-compile our Python interpreter to Nokia's
     Maemo platform:

   - Some effort was spent to make the Python interpreter more
     memory-efficient. This includes the implementation of a mark-compact
     GC which uses less memory than other GCs during collection.
     Additionally there were various optimizations that make Python
     objects smaller, e.g. class instances are often only 50% of the size
     of CPython.

   - The support for the trace hook in the Python interpreter was
     improved to be able to trace the execution of builtin functions and
     methods. With this, we implemented the ``_lsprof`` module, which is
     the core of the ``cProfile`` module.

   - A number of rarely used features of PyPy were removed since the 
     release because they were unmaintained and/or buggy. Those are: The
     LLVM and the JS backends, the aspect-oriented programming features,
     the logic object space, the extension compiler and the first
     incarnation of the JIT generator. The new JIT generator is in active
     development, but not included in the release.

What is PyPy?

Technically, PyPy is both a Python interpreter implementation and an
advanced compiler, or more precisely a framework for implementing 
dynamic languages and generating virtual machines for them.

The framework allows for alternative frontends and for alternative
backends, currently C, Java and .NET.  For our main target "C", we can
"mix in" different garbage collectors and threading models,
including micro-threads aka "Stackless".  The inherent complexity that
arises from this ambitious approach is mostly kept away from the Python
interpreter implementation, our main frontend.

Socially, PyPy is a collaborative effort of many individuals working
together in a distributed and sprint-driven way since 2003.  PyPy would
not have gotten as far as it has without the coding, feedback and
general support from numerous people.

Have fun,

     the PyPy release team, [in alphabetical order]

     Amaury Forgeot d'Arc, Anders Hammerquist, Antonio Cuni, Armin Rigo,
     Carl Friedrich Bolz, Christian Tismer, Holger Krekel,
     Maciek Fijalkowski, Samuele Pedroni

     and many others:

More information about the Python-announce-list mailing list