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PyPy3 5.5.0 released

We're pleased to announce the release of PyPy3 v5.5.0. Coming four months after PyPy3.3 v5.2, it improves compatibility with Python 3.3 (3.3.5). We strongly recommend updating from previous PyPy3 versions.

We would like to thank all of the people who donated to the py3k proposal for supporting the work that went into this release.

You can download the PyPy3.3 v5.5.0 release here:

  • Improved Python 3.3.5 support.
    • os.get_terminal_size(), time.monotonic(), str.casefold() 
    • faulthandler module
    • There are still some missing features such as a PEP 393-like space efficient string representation and including performance regressions (e.g. issue #2305). The focus for this release has been updating to 3.3 compatibility. Windows is also not yet supported.
  • ensurepip is also included (it's only included in CPython 3 >= 3.4).
  • Buffer interface improvements (numpy on top of cpyext)
  • Several JIT improvements (force-virtual-state, residual calls)
  • Search path for has changed (helps with cffi embedding on linux distributions)
  • Improve the error message when the user forgot the "self" argument of a method
  • Many more small improvements, please head over to our documentation for more information

Towards Python 3.5

We have started to work on Python 3.5, which is a version used by many software projects. It seems to get wide adoption. We are happy to be part of the Mozilla Open Source Support (MOSS) initiative.

Nevertheless we want to give our users the chance to use PyPy in their Python 3 projects, thus we have prepared this release.

What is PyPy?

PyPy is a very compliant Python interpreter, almost a drop-in replacement for CPython 2.7.10 and 3.3.5. It's fast 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 except Windows 
  • newer ARM hardware (ARMv6 or ARMv7, with VFPv3) running Linux 
  • big- and little-endian variants of PPC64 running Linux 
  • s390x running Linux
Please try it out and let us know what you think. We welcome feedback, we know
you are using PyPy, please tell us about it!


The PyPy Team


Mak Sim wrote on 2016-10-13 07:51:

Great! Wayting for windows build.

Anonymous wrote on 2016-10-14 05:08:

Excellent news. Thank you!

Butla wrote on 2016-10-17 15:52:

Wow! 3.5? That would be incredible. Shouldn't there be more hype around JITted asyncio applications?

Unknown wrote on 2016-10-21 07:49:

I was really touched.

Unknown wrote on 2016-11-06 01:19:

Butla: I do totally agree, pypy not only for numeric code anymore but also for parallel production servers.

Unknown wrote on 2016-12-02 15:49:

The performance difference between 5.5 and 5.2 is awesome! For my heavy string and lists-of-strings processing tool, 5.5 needs about 25% less time for the same task. Thank you so much!

Dagur wrote on 2017-05-24 14:08:

What is the status on windows support?