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Grumpy: Go running Python

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Re: Grumpy: Go running Python

#341

Post by pdonis »

trotterdylan wrote: post #169
Walkman wrote: post #142

Earlier quoted context omitted.

Is there not a single namedtuple in the entire Google codebase? That's strange :o

Heh, I came across the namedtuple exec thing the other day when I was trying to get the collections module working :\ namedtuple will have to be implemented differently. I think it can be accomplished by defining the class with type()? Maybe with a metaclass...

> I think it can be accomplished by defining the class with type()?

I've done it using more or less that method. The code is in the "coll" sub-package of my plib.stdlib project; the Python 2 version is here on bitbucket:

https://bitbucket.org/pdonis/plib-stdlib/src

Re: Grumpy: Go running Python

#342

Post by kj01a »

cdelsolar wrote: post #281
kj01a wrote: post #203

Earlier quoted context omitted.

>(Yes, I'm still on Python 2 but moving soon). I'm like really new to programming and I'm still just learning the basics, but I see this little addendum a lot from people who say everyone should be writing Python 3.

It's true, but moving our huge codebase to Python 3 is a big undertaking. We're making progress towards it by using Python 3 constructs for new files, etc. For my personal projects I'm already in the process of moving over.

So is it just a time issue, or are there compatibility reasons for why not all of you code is Python 3?

I ask because I started to learn to code with Python 2 because that's what was preloaded on my system. Is one over the other a big enough deal at a beginner level that I should switch to 3 now? How much of a learning curve am I in for?

Re: Grumpy: Go running Python

#343

Post by mastazi »

kj01a wrote: post #342
cdelsolar wrote: post #281

Earlier quoted context omitted.

It's true, but moving our huge codebase to Python 3 is a big undertaking. We're making progress towards it by using Python 3 constructs for new files, etc. For my personal projects I'm already in the process of moving over.

So is it just a time issue, or are there compatibility reasons for why not all of you code is Python 3? I ask because I started to learn to code with Python 2 because that's what was preloaded on my system. Is one over the other a big enough deal at a beginner level that I should switch to 3 now? How much of a learning curve am I in for?

> Is one over the other a big enough deal at a beginner level

No, at a beginner level it's not, there are many guides that explain the differences at a beginner level, and you can go through those in a few hours at most, for example http://python-future.org/compatible_idioms.html

But, if you start working now on a Python 2 project and that project starts growing significantly, then it will be hard to convert the codebase. That's why you can see people saying that they didn't switch yet, it's not that they don't know Python 3, it's that upgrading large legacy code bases is hard (not only in Python).

Re: Grumpy: Go running Python

#345

Post by earthboundkid »

beagle3 wrote: post #242
joshuata wrote: post #64

Earlier quoted context omitted.

In regards to the third point: The global interpreter lock protects the fact that python's GC scheme is not thread safe. It does not coordinate accesses across threads, and therefore grumpy's would not either. In grumpy the GIL is replaced by Go's GC implementation that is specifically tuned for multithreaded execution. Any additional synchronization would need to be done with individual locks etc...

The GIL is not just for GC; it does coordinate access across threads, albeit at a very low level -- if two threads execute "mylist.append(v)" at the same time, it is the GIL that makes sure it actually works as expected, and from comments above it seems grumpy uses per-object locks for that.

That's not a good characterization of the GIL. It doesn't prevent races or make multithreaded mylist.append safe. It makes sure that mylist.append doesn't cause a segfault as the bytes in RAM are in an inconsistent state during an update. Beyond that, it doesn't really protect you from your bad threaded code.

Re: Grumpy: Go running Python

#346

Post by earthboundkid »

TillE wrote: post #66
Animats wrote: post #48

- Amusingly, it runs Python 2.7, even though this project started long after Python 3.x came out. - It's a hard-code compiler, not an interpreter written in Go. That implies some restrictions, but the documentation doesn't say much about what they are. PyPy jumps through hoops to make all of Python's self modification at run-time features work, complicating PyPy enormously. Nobody uses that stuff in production code,…

> Nobody uses that stuff in production code Nobody uses the features of Python which make it a dynamic language? Google must write some really weird Python if their compiler is that strict.

I have never used exec or eval in production Python, and I doubt I could get them past code review because of the possible security impact.

Re: Grumpy: Go running Python

#347

Post by kj01a »

mastazi wrote: post #343
kj01a wrote: post #342

Earlier quoted context omitted.

So is it just a time issue, or are there compatibility reasons for why not all of you code is Python 3? I ask because I started to learn to code with Python 2 because that's what was preloaded on my system. Is one over the other a big enough deal at a beginner level that I should switch to 3 now? How much of a learning curve am I in for?

> Is one over the other a big enough deal at a beginner level No, at a beginner level it's not, there are many guides that explain the differences at a beginner level, and you can go through those in a few hours at most, for example http://python-future.org/compatible_idioms.html But, if you start working now on a Python 2 project and that project starts growing significantly, then it will be hard to convert the code…

Okay. Thank you for the advice.

My biggest program is like 100 lines of code maybe. So I will go ahead an switch now. But it's like 10pm where I'm at so here's hoping I don't play too much...

Re: Grumpy: Go running Python

#348

Post by johnny22 »

kj01a wrote: post #342
cdelsolar wrote: post #281

Earlier quoted context omitted.

It's true, but moving our huge codebase to Python 3 is a big undertaking. We're making progress towards it by using Python 3 constructs for new files, etc. For my personal projects I'm already in the process of moving over.

So is it just a time issue, or are there compatibility reasons for why not all of you code is Python 3? I ask because I started to learn to code with Python 2 because that's what was preloaded on my system. Is one over the other a big enough deal at a beginner level that I should switch to 3 now? How much of a learning curve am I in for?

what system is that? a mac? If so , the sadly you do have to get py3 yourself. If a Linux distro, then you likely already have python 3 preinstalled. `/usr/bin/python` won't point to python3 in anytime in the near future.

Re: Grumpy: Go running Python

#349

Post by sfifs »

SureshG wrote: post #309
derefr wrote: post #235

Earlier quoted context omitted.

> I don't know that this makes sense for anyone but Google I'm not sure; as a Go developer, I kind of like the idea of having access to the Python library ecosystem from Go, without being forced to create an IPC bridge and building up the requisite release-management and deploy-time goop. Plus, I'm just not a Python developer; in the case where the only library that exists to do something is written in Python, I'd mu…

IIUC, it's not about accessing python libs from go. It's for accessing go libs from your python program and transpiling that python code to go source and compile it with go tool chains. Eg: python code (from blog post) from __go__.net.http import ListenAndServe, RedirectHandler handler = RedirectHandler('http://github.com/google/grumpy', 303) ListenAndServe('127.0.0.1:8080', handler)

sure but the reverse should be equally feasible. It's transpiling Python to Go, so theoretically we should be able to (eventually) "convert" Python libs to Go and call them from Go. A lot of utility libs are available in Python... the Go library ecosystem is relatively sparse

Re: Grumpy: Go running Python

#350

Post by jonathanyc »

lobster_johnson wrote: post #174
ericfrederich wrote: post #25

Python needs a new runtime. This talk shows how bad of shape it's really in. https://www.youtube.com/watch?v=qCGofLIzX6g&list=PLRdS-n5seL... Basically, the language doesn't have a "spec" per-se. The language is whatever the defacto CPython implementation happens to do within it's giant eval loop. Another great talk about CPython internals: http://pgbovine.net/cpython-internals.htm

The reference [1] is a decent spec. It might not be as formally rigorous as an ISO standard, but it's probably as good as Go's [2], which also a "reference". [1] https://docs.python.org/3/reference/index.html [2] https://golang.org/ref/spec

In my experience with both languages, while the Go spec is incredibly readable, navigable, and succinct, the Python reference is a sprawling mess that is difficult to navigate or even to Ctrl-F in.
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