PyPy v7.0.0: triple release of 2.7, 3.5 and 3.6-alpha


198 points | by rlamy 187 days ago


  • qeternity 187 days ago

    Great news, will have to give it a spin. A few of the Python 3.6 features were holding us back from deploying PyPy.

    • fifnir 187 days ago

      How's pypy with numpy these days? It's been a while since I had a look and last time it was the big limiting factor for me

      • fijal 187 days ago

        numpy works on pypy these days. You have to install it via pip and it does not have wheels, so it takes a few minutes to install, otherwise works. The numpy-heavy workloads will not be sped up by pypy, but depending on what you are exactly doing your python program might be faster in other parts.

        We are actively trying to secure funding and goals to make numpy fast, now that it works and we are working together with numpy community to make sure it stays working.

        • qeternity 187 days ago

          IIRC, PyPy is actually slower on pure CFFI calls, so anything that is mostly Numpy/Pandas/Scikit will likely be slower in PyPy. At least this was the case when we were using PyPy 3.5.

          But often the rest of your code base will experience dramatic increases in performance, and the penalty on already fast CFFI calls was not significant overall (in our use case).

          • fijal 187 days ago

            I think you are confusing CFFI (which is massively faster under pypy) with CPython C API calls (which is both slower under pypy and ones used by numpy)

          • sandGorgon 187 days ago

            Do you have a donate link ? Would love to contribute.

            Usually your donate links are mentioned on your blogspot and more than one person has told me that they are not sure this blogspot is authentic.

            Do look into having a single static website with a blog - using something like Pelican (

            • eesmith 187 days ago

              Why does it matter if this blogspot is authentic? The "Donation page" link is to which is hosted under

              The blog could be written by Trafalmadorian trolls, and it wouldn't matter - so long as you trusted that "" was part of the PyPy project and that its connection to PayPal was valid.

              I don't think your last comment is relevant. What I think you are saying is that the blog should be hosted under and not blogspot. It could be WordPress or any other system.

              It couldn't easily be Pelican because the blog supports comments, which means integrating with some other commenting system - plus authentication and spam detection. Why not get rid of the hassle of manually adding files and rebuilding the server and just use blogspot?

              Lastly, are you really saying that people aren't donating to PyPy because some supportive blog site somewhere else, run by who knows who, isn't hosted on

              • sandGorgon 186 days ago

                yeah - because people dont go to the homepage. what gets tweeted out is this blogspot page (including here on HN). So people check out the nice blog post and see a donate link on the left of and then go ...hmm, looks shady.

                Not many read the blog post, then go to Google, search for pypy and then click the link and then donate.

                Fundraising is not an easy process - there is an aspect of sales here. Blogspot may be easy.. but its not good branding. And that was my point - cos I want them to succeed.

                • eesmith 186 days ago

                  Please explain how it looks shady, because I don't understand it.

                  If I start a blog - completely independent of PyPy - which promotes PyPy and describes the development efforts, and I want to encourage people to support the PyPy project, then I might link to the PyPy donation page, yes?

                  Yet, because I'm not affiliated with the project, I can't put the blog under

                  Would my blog also be shady? If so, doesn't that mean that no one should promote donating to a project unless that promotion is done under the project's domain?

                  You write "Not many read the blog post, then go to Google, search for pypy and then click the link and then donate."

                  That would be true even if the blog post were hosted under That is, why would anyone donate after reading one blog post?

                  I would think that more people would donate after they download PyPy, try it out, and see that it's worthwhile enough to fund.

                  In that case, they've already found out how to get PyPy, so there's no need to "Google, search for pypy" because they've already done that.

                  Nor is PyPy unusual in this respect. It's hard to find projects which have both a blog and a donate page. Of the 50 so projects I looked at, the following are "shady" according to your definition:

                  - the PSF blog (hosted on blogspot) links to the page for donations, eg, .

                  - The Thunderbird blog has a posting like linking to while the main Thunderbird page is at


                  - Orange, with a blog at is a sibling subdomain to the main project site at , making it ... semi-shady? I mean, how are we to know that "" is not some sort of large ISP where any of their customers can make a subdomain?

                  I did find a two places where the "donate" and "blog" pages were hosted on the same domain: (which links to a SourceForce page which redirects to PayPal) and .

                  To summarize, I don't see why it's shady, your view seems to mean that no one should promote donating to a project except for the project itself, static site generation tools don't seem to be a good fit for blog support, and it doesn't seem like the effort to change to a single domain would have a worthwhile effect on improving the donation rate.

                  • sandGorgon 186 days ago

                    your examples are weird - and ill try to explain if i wasnt able to. I'm not saying that the blog is bad and you are explaining why the blog is good.

                    I'm saying it is hosted on blogspot and there is another main site which is a . People dont think the way you do. Try it out - ask 10 people if they would open this blogspot page and ever click on the donate link. Pypy's blog is not shady - blogspot as a free hosting service is shady.

                    your examples of mozilla, etc blogs are super orthogonal - they are hosted on an authoritative domain. Again, I'm repeating - it has nothing to do with pypy. Its about blogspot.

                    You are again attacking my suggestion of static site - the reason i suggested that was because it was a python based site generator with a CMS. you can try to do a wix site or whatever. As long as its an authoritative domain.

                    Its not about me - its how people thing. You should go and check.

                    • eesmith 186 days ago

                      Now you, "ask 10 people if they would open [the] page and ever click on the donate link".

                      I think the answer is "very unlikely", which is why I don't think your example is a useful diagnostic.

                      I also don't think "authoritative domain" is meaningful. What does it mean to be "authoritative" and how do people tell if a domain is authoritative?

                      I gave the examples of and - is "" authoritative enough to know that both subdomains are part of the same project, if pointed to ?

                      Let's stay in the same top-level domain. Is authoritative? What about If so, what does that mean? That we can trust paths under that domain to be part of the project?

                      I note that and both exist, but neither are ways to donate to the respective projects. So the answer is clearly "no".

                      Indeed, it looks like someone could set up as a place to describe GitLab development, and set up as a way to donate, and yet have nothing to do with GitLab.

                      So if someone read a blog post under, then they still can't trust the donate link but must instead, as you wrote earlier "go to Google, search for [gitlab] and then click the link and then donate" .. though neither takes donations on their home page.

                      How is the PyPy situation any worse by not hosting the blog on a non-authoritative URL?

              • llukas 187 days ago

                Click donate here:

              • psandersen 187 days ago

                Will scikit learn and pandas work without issue as well? Keen to try PyPy once I can run a typical data science stack.

                • sanxiyn 187 days ago

                  Yes, both scikit-learn and pandas should work with PyPy.

                • _verandaguy 187 days ago

                  Thanks for all the work you guys are doing! PyPy has been a case study in learning about JITs and alternative Python implementations for me over the past few years.

                • Gladdyu 187 days ago

                  I've attempted to run it (not with this latest release yet though) and it appeared as if calling a numpy function essentially disabled the JIT for that function, which was not acceptable for us at that point. What did seem to help curiously was wrapping the numpy function in a python function and then calling that, which seemed to prevent the JIT being disabled in the calling function.

                  • qeternity 187 days ago

                    Curious why? We use numpy is easily optimizable areas so there's very little python code, and JITing a call to a C library is pointless.

              • bratao 187 days ago

                PyPy is fantastic. I'm my option, if they achieve to be faster than CPython in all scenarios( I'm thinking in Numpy/Scikit/Pandas CPython C API abuse), and get full Windows support (they do not support multiprocess in Windows), they WILL be the preferred Python Runtime.

                Congratulations PyPy team for the great release!

                • chc 187 days ago

                  I doubt they'll ever get even as fast as CPython for CPython API usage. What allows PyPy to run Python code fast is the same thing that makes the CPython API slow: The two implementations look nothing alike on the inside. The API is too leaky an abstraction to implement efficiently on anything but CPython.

                  • fijal 187 days ago

                    While I agree with you, pypy already runs cffi fast and we are thinking how to run cython fast. That would cover a large subset of using C API I think.

                • fake-name 187 days ago

                  Awesome. And they're finally pushing pypy3 in their Ubuntu PPA too (!

                  I use pypy3 pretty heavily in some personal projects, and the install process has always been extremely annoying. This is great!


                  I wish they'd set up a CI-build PPA (or any install process that's not just "wget binary").

                  I actually looked at setting up my own ppa at one point, but it's apparently involved enough that I didn't have time.

                  • nikolay 187 days ago

                    If I was PyPy, I'd have dropped all 2.x effort and focused on Python 3.8 compatibility.

                    • wyldfire 187 days ago

                      Actually, there's been quite some speculation that PyPy could inherit the 2.x crown when CPython expires its support for 2.x (1 Jan 2020). PyPy is probably the best non-CPython Python 2.7 implementation, so it's a natural fit to some degree. I suppose it's all dependent on where the PyPy team wants to spend its time and whether or not someone might fund them for this effort (Canonical, RH, etc).

                      I don't know that they have the will to bug-for-bug reproduce CPython but the C API emulation layer added within the last few years probably means that it will be really high fidelity.

                      • nikolay 187 days ago

                        Well, this whole Python 2 & 3 is a huge fiasco. Supporting 2.x keeps the circus forever on.

                        • wyldfire 187 days ago

                          I don't know that I agree that it's a fiasco. I've been asked to work on a PDP11 in the last few years and while it was mind-boggling (the request -- I turned it down), it was understandable from a business perspective. So I can see how some businesses might want Just A Little While Longer on Python 2.x.

                          shrug, use python 3.x and don't sweat the fact that some folks are still stuck on 2.x. You certainly can't stop someone from offering support for 2.x -- the language is well defined and the reference implementation is open source. Anyone out there could put up a "Python 2.x Support: Cheap!" sign and be in business.

                          • nikolay 187 days ago

                            It surely is. There's a reason behind why support for old versions ends at some point.

                          • josefx 187 days ago

                            Reinventing the wheel keeps the circus going forever. As long as python 2 is supported I don't have to touch any of the scripts I have to "maintain". The moment I am forced to migrate everything to Python 4 (they broke everything already, why not again) I will have to deal with a huge amount of pointless busywork just trying to restore functionality.

                            • aldanor 186 days ago

                              Python 4 will not "break everything again", it will be equivalent to a point release. It has been already explicitly mentioned.

                              • nikolay 187 days ago

                                Yeah, this is how to world moves forward - otherwise, we'd all be still watching VHS movies. Plus, there's this lovely tool called 2to3.

                                • josefx 187 days ago

                                  Funnily I can still watch VHS movies on a relatively new TV. Just had to plug in the VHS recorder and play, meanwhile the description of 2to3 makes it look like a plug and pray.

                                  I mean really? A script that might mention some cases it can't fix as warnings. "optional" fixes that replace missing classes with incompatible replacements, giving you the "choice" of fixing the mess by hand. Also an apparently unstable API for your own fixes, doubling down on breaking your code while you try to fix your broken code has to be dedication.

                                  > Note The lib2to3 API should be considered unstable and may change drastically in the future.

                                  • nikolay 187 days ago

                                    Well, 2to3 works surprisingly well and I've converted tons of projects with it. Most major Python projects support both 2 and 3, so, private codebases, which "just work", should stay on the "just working" old versions of the interpreter instead of insisting maintainers to waste time entertaining their laziness, because things that "just work" don't require ANY updates, right?

                                    • josefx 186 days ago

                                      I am happy as long as I can plug-in old versions of the interpreter in a system 10 years from now as easily as I could plug-in my VHS recorder into the TV. Might be able to do that if I install a windows version of python on Wine, there is a good chance (~100%) that the dependencies of python on Linux will not remain compatible that long.

                                      • nikolay 186 days ago

                                        Yeah, but dependencies are another story. So, my point is, if something "just works" and you don't want to have to upgrade, you need to freeze the entire system with all dependencies, which includes hardware, OS, etc. Everything else is just an illusion.

                                        I sill have people using my Win16-based software written using Borland Pascal with Objects I wrote 30 years ago. They keep changing power supplies, etc. of an old system, but recently they had some major hardware problem and asked me to help them. I couldn't and wouldn't.

                                        They ended up somebody creating a VM from their hard drive, and they are happy now and can back up that image and keep the circus going on forever.

                                • nikolay 187 days ago

                                  What's the problem to stay on the "just working" version of Python and not feel entitled to get updates?!

                                  • reitzensteinm 187 days ago

                                    The only entitlement here comes from you.

                                    If pypy wants to support 2, they can. If developers want to take advantage of that, they can. If library maintainers want to drop 2 support, they can. If others want to fork the libraries to provide security for the 2.x fork, they can.

                                    What is not acceptable is trying to dictate what technology others choose to use to suit your personal preference.

                                    • nikolay 187 days ago

                                      Well, there's demand for McDonald's today as well, and people happy to supply to meet it! The Python community has dragged this circus for way too long it is now finally being put to an end. But there always will be dinosaurs who won't embrace progress and innovation, of course.

                                  • reitzensteinm 187 days ago

                                    I could kiss this comment. You don't have a right to stop other people using py2 just so your ecosystem is a little cleaner. Yet that level of entitlement is apparently not uncommon in Python discussions.

                              • fijal 187 days ago

                                There are two things in play here - one is that pypy is a large py2-only codebase that is unlikely to be ported. Second is that maintaining python 2 both does not cost much and it's used by the majority of our users, despite of what you hear on the internet. So, there is both good reason to keep it and a large amount of work to drop it.

                                • chc 187 days ago

                                  I might be mistaken, but it was my impression that the changes to the 2.7 version now are mostly "core" changes that also apply to PyPy3. Basically, most language-specific work is going toward Python 3, and PyPy2 benefits when features they have in common are improved.

                                  • 0xADEADBEE 187 days ago

                                    It'll be interesting to see if there's an upswing in PyPy usage over the next few months, for the explicit reason that they're not slated to drop 2.7 compatibility. I would imagine a noticeable percentage of 2.7 codebases without the available resources for a rewrite (that has by definition, no business value) would welcome anything close to a drop-in replacement. I'll be very interested to see if I'm wrong though!

                                  • maayank 187 days ago

                                    What's the word on 3.7 support?

                                    • fijal 187 days ago

                                      3.7 (or maybe even 3.8) support will start as soon as we can have a "final" 3.6 - which might be couple months from now. I think 3.7 won't be done in 2019, unless some magic source of funding pops up.

                                      • alerighi 187 days ago

                                        3.7 it's a minor update from 3.6, that basically consists in changes to the standard library rather than the language, and 3.8 I think it will be the same, so once the 3.6 support is implemented it will take less time to implement 3.7 support.

                                      • make3 187 days ago

                                        how isn't Google or Dropbox or Instagram not completely funding you

                                        • muizelaar 187 days ago

                                          Google and Dropbox have been migrating from Python to Go to deal with Python's performance problems instead of trying to make Python run faster.



                                          • fijal 187 days ago

                                            The main way big corpos are sponsoring os is hiring the developers typically. That comes with a whole lot of things that some people don't want to deal with, like changing your place of residence

                                            • rurban 187 days ago

                                              Zurich or Munich shouldn't be too bad, isn't it?

                                              • sanxiyn 187 days ago

                                                Why not Cape Town?

                                                • rurban 187 days ago

                                                  I doubt that they allow you to work on a VM there. I saw only marketing and content jobs there. In Munich or Zurich they do have VM teams. Maciej is from Warsaw, he could do surfing in Munich. Armin Rigo is in Switzerland.

                                                  • fijal 187 days ago

                                                    I live in Cape Town where I can do surfing a bit better than in Munich ;-)

                                                    • rurban 187 days ago

                                                      Sure, also much cheaper. But Munich has no sharks, and the wave is much easier to catch, and it's easier to train 360's :) The Zurich wave is not that good.

                                            • jhasse 187 days ago

                                              I guess they aren't the ones that are using 3.7 anyway.

                                              • ijpoijpoihpiuoh 187 days ago

                                                Does Google use PyPy at all? I wasn't aware.

                                                • make3 187 days ago

                                                  maybe they could if they funded it to do what they need it to do

                                              • maayank 187 days ago

                                                How realistic is it for an experienced programmer to dedicate 4 hours a week and join as a contributor? Not sure it is enough to bootstrap enough "project" domain experience to be productive. Asking for a friend.

                                                • mattip 187 days ago

                                                  There are some “easy” tasks to achieve 3.6 full compatibility, tell your friend to try it and see. We are around on #pypy on IRC, mostly european timezones

                                            • entilzha 187 days ago

                                              Anyone know if puppy works with deep learning libraries like pytorch/tensorflow, or if there are plans to do so? Not looking for numerical speed ups, but for speed ups in preprocessing code

                                              • man-and-laptop 187 days ago

                                                I don't have a suitable workload with me right now. Has anyone tested the performance of PyPy3 vs PyPy2? Last time I tested it on a problem, PyPy2 was significantly faster (at least x3). That was maybe one or two years ago, when it was in beta.

                                                • medecau 187 days ago

                                                  As usual it depends. But pypy3.5-6.0.0 is fast enough for me that I now prefer it over pypy2.7-6.0.0.

                                                • gamesbrainiac 187 days ago

                                                  Anyone using pypy in production? If so, what are your experiences like?

                                                  • rciorba 187 days ago

                                                    I did do but not for anything high traffic.

                                                    At work we had this internal service that did search entirety in memory, using sorted lists. When it was initially written, years ago, that was deemed "good enough".

                                                    By the time I joined the company a little over a year ago, search requests were sometimes exceeding 2 minutes, and would be killed due to HTTP timeout (somehow users were OK with search taking a long time, they were just annoyed that now sometimes it didn't work at all). While I was working to rewrite the whole thing to push data to ES and do everything from there, the old system needed to keep running.

                                                    So I moved it over to PyPy. I did need to swap blist(C extension) for sortedcontainers (pure python), but that was a minimal change. Search got about 30% faster, enough to keep chugging along while the rewrite happened.

                                                    • chc 187 days ago

                                                      The place where I work uses it for back-end report generation. In my experience, PyPy's claimed speed benefits are very realistic. For most of our code, we get about a 3x speedup. For some areas of code, we get up to a 7x speedup. The only compatibility issues we've run into stemmed from mistakes on our part (e.g. all dicts are effectively OrderedDicts in PyPy, but your code will break in CPython if you rely on that implementation detail).

                                                      As a side note, for some reason, it's terrible for pytest — your tests will take literally 100x as long. If you trust PyPy's compatibility, I'd recommend running your tests with CPython even if you run PyPy in production.

                                                      • ris 187 days ago

                                                        > all dicts are effectively OrderedDicts in PyPy, but your code will break in CPython if you rely on that implementation detail

                                                        Actually since CPython 3.6 (or maybe it's 3.5?) the same is true in CPython too, though I'd personally still advocate specifying OrderedDict if you particularly require that property anyway.

                                                      • sanxiyn 187 days ago

                                                        We used PyPy in production. It sped up workload loading JSON-per-line log to Amazon Redshift by factor of two with no changes.

                                                        • krautsourced 187 days ago

                                                          For what it's worth, I was using it for a Django project and it did speed up noticeably - but I also ran into mysterious crashes. Now, I can't pin it to pypy necessarily, might have been some Django lib not playing ball with pypy. Had no time to test it in depth because moving back to regular Python was "good enough".

                                                        • scarygliders 187 days ago

                                                          I wish PySide (and/or PySide2) would work with PyPy. It looks like (after a cursory search) some version of Gtk can be used but I prefer Qt over Gtk.

                                                          • lazka 186 days ago

                                                            For gtk, gstreamer etc. PyGObject should just work. It has PyPy as part of its CI pipeline. Also in combination with matplotlib (GTK3Cairo backend) and numpy.

                                                            Not sure about PySide2..

                                                            • scarygliders 185 days ago

                                                              Thanks, but I mentioned I don't want to use Gtk. I've not had a particularly joyous time with Gtk in the past and therefore chose Qt as my GUI platform of choice over Gtk.

                                                              Therefore until and unless PyPy has usable Qt bindings (e.g. PySide or PyQt), then unfortunately I need to stick with CPython :/

                                                              • lazka 185 days ago

                                                                Yeah, sorry. It shows at least that it's possible with the current PyPy C API layer to have GUI bindings working.

                                                                Here is the only PyPy related issue I found for PySide2:

                                                                PyQt doesn't have a bug tracker ¯\_(ツ)_/¯

                                                          • truth_seeker 186 days ago

                                                            Cool. Does anybody have an idea How Django or Flask web app can be benefited from overall performance perspective ?

                                                            • xvilka 187 days ago

                                                              I personally think that Rust port of CPython has the bigger potential than PyPy.

                                                              • jlarcombe 187 days ago

                                                                Why? Isn't the clever bit the JIT, rather than the implementation language?

                                                                • chc 187 days ago

                                                                  Why do you think so? Rust is an interesting language in itself, but I don't see why you'd expect a Rust port of CPython to compete with PyPy in terms of performance. It's still, at its core, the CPython architecture.

                                                                  • miohtama 187 days ago

                                                                    Does it aim for security and correctness? As the interpreter has hard time to keep up with JIT in the speed race which I believe is the major driving force behind PyPy.