Jython - Using Spring, Programming in Python? - python

Ok, I'm a total newbie in this stuff.
So, I know Spring is really good as a framework, and I've been programming in Python for a while, so I was wondering if somehow I can use the Spring Framework but use code from Python.
I heard that maybe Jython was a good possibility for doing this, since it's (I think) Python running on the JVM, right?
So, is this possible? For me to use Spring while coding in Python?

First, you're right that Jython is Python running in the JVM. And it's not just running in the JVM, it can interact with it in pretty much all the ways you want—use Java classes as Python classes, implement Java interfaces in a Python class and pass it to Java code, etc.
However, unlike some of the other JVM languages, Jython doesn't make any attempt to be semantically equivalent to Java (or to a superset of it). And of course Python and Java have very different idiomatic styles.
So, in short, just about anything is possible, but not everything is pleasant, as Marcin says.
For specifics about how Spring works with Jython, a quick Google search turned up See how Spring Python works with Jython. And in fact, it's part of a blog called "Spring Python", which is part of a site also called "Spring Python". It seems like this may be a port of Spring to Python rather than about using Jython with Spring. ("This project takes the concepts of Spring and applies it to the language and environment of Python. This includes pragmatic libraries and useful abstractions that quickly gets you back to working on the code that makes you money.") So, that might be another alternative for you.
The next search result was Jython Spring MVC Controllers.
And there were half a dozen other promising results. So, I think you'll have no problem finding information and examples.

Related

clojure working with scipy and numpy

Is there any good way to call python from clojure as a means of doing data science with scipy, numpy, scikit-learn, etc.
I know about implementations of clojure which run on python instead of java, but this doeesn't work for me, as I also need to call java libraries in my project. I also know about Jython, but I don't know of a clean way to use this with Clojure.
I want to use Clojure in my projects because I prefer it as a language, but I can't deny that Python has an incredible community, and some of the most beautiful, well-designed libraries around.
Instead of trying to get Jython to play well with both Clojure and numpy/scipy, you can use Hy. It is hosted on Python and it somewhat resembles Clojure.
If I really wanted to use numpy/scipy, I would write the backend in Python (or Hy), run it as a separate service. And if I really like ring for instance, or can't live without Instaparse, I would write a frontend in Clojure.
As an aside Python has EDN libs. It would be an interesting project to integrate one of them in Hy, or write one from scratch.
Give the toolz library a try, it's a functional standard library for Python that was designed to generally adhere to the API of the Clojure standard library.
Apart from that, I'd encourage you to find the seams between your computations, and write individual tools in the Unix way in either Clojure or Python depending on which seems to fit that use case best. Serialize data between the tools, either as text/JSON through pipes or using a binary serialization format like Protobuf, which has standard APIs for both Java and Python.
If you had a gun to my head and told me to build Clojure/Python interop, I'd start with py4j and bridge the two languages through Java interfaces, using implements members in a Python class and reify on the Clojure side.
You could use Graal VM now. Although some large companies are using it in production, it's still early days. Here's an example of using Python from Clojure:
(.eval context "python" "
import time;
time.clock()
")
http://gigasquidsoftware.com/blog/2017/10/22/embedded-interop-between-clojure-r-and-python-with-graalvm/

PC^2 equivalent compatible with Python

I will be running a programming competition for high school students in the near future, and was originally going to use PC^2 (Programming Contest Control System) for the automated judging of the solutions. This software is commonly used in the ACM's International Collegiate Programming Contest regionals as well as the world finals. This is an excellent system which I have used before, but one of its pitfalls is its language support (Java, C, and C++). I'm a little bit concerned, as not all high school students who may be attending will have exposure to any of these languages. However, many local high schools teach introductory programming courses in Python. Is there an equivalent system to PC^2 which has Python support?
You can use some open source implementations of the online judges.
for example ONJ http://sourceforge.net/projects/onj/
It is easy to configure and it can be made compatible to run on languages of your choice. You dont need local copies of it on every system where the students will sit, you can just run it on a server and give the students its web-link to submit their solutions.
Do it with Sphere Online Judge, contest hosting is free of charge, many languages available.
I actually found a much better way to accomplish this. In their latest release, PC^2 added support for interpreted languages (such as Python, etc). Since PC^2 requires an executable, you need to "stub out" the compile command and simply invoke the interpreter with the script.
The full guide can be found at http://pc2.ecs.csus.edu/wiki/Interpreted_languages
Assuming you are still interested, PC^2 is very adaptable. I run a scripting contest using it and support Python, Perl, PHP and Ruby. Basically, PC^2 expects a language to compile and then run. You need to write a dinky script that pretends to compile the code and return success. Then the run script simply runs the scripting submission. Pretty easy to do.
You can visit http://acm2012.scusa.lsu.edu and look at the scripting contest info. Feel free to contact us for more info.
It's simpler than one may think. The following is for pc2 9.2.3-2565
Add language as follows (python here as an example):
Display Name: Python
Compile Cmd Line: touch OK
Executable Filename: OK
Program Execution Command Line: python {:mainfile}
python3.3 or python3.4 will work too.
pc2 could be easier, of course, but there does not seem to be much support left at CSUS. Reseting contest would be even greater feature; the current need to clone directories for test, practice, and actual contest is very awkward. Better management of the database (like the ability to remove things) would make it into a great tool. It is alright, but it could be great.

Real-world Jython applications

I recently started learning Python. Not yet ventured into coding.
During one of my learning sessions, i came accross the term Jython.
I googled it & got some information.
I would like to know if anyone has implemented any real-world program using Jython.
Most of the time, Jython isn't used directly to write full read-world programs, but a lot of programs actually embed Jython to use it as a scripting language.
The official Jython website gives a list of projects, some written in Jython, others using Jython for scripting:
http://wiki.python.org/jython/JythonUsers
I am writing a full application in Jython at the moment, and would highly recommend it. Having all of the Java libraries at your disposal is very handy, and the Python syntax and language features actually make using some of them easier than it is in Java (I'm mostly talking about Swing here).
Check out the chapter on GUI Applications from the Jython book. It does a lot of comparisons like 'Look at all this Java code, and now look at it reduced to Python code of half the length!'.
The only caveats I've found are:
Jython development tends to run slightly behind Python, which can be annoying if you find a cool way of doing something in Python, only to discover it's not supported in the current Jython version.
Occasionally you might have hiccups with the interface between Python and Java (I have a couple of unsolved problems here and here, although there are always workarounds for this kind of thing).
Distribution is not as simple as it could be, although once you figure out how to do it, it's fairly painless. I recommend following the method here. It essentially consists of:
Exploding jython.jar and adding your own modules into it.
Writing and compiling a small Java class that creates a Python interpreter and loads up your Python modules.
Creating an executable .jar file consisting of the jython.jar modules, your own Python modules, and the Java class.
Jython really shines for dependency injection.
You know those pesky variables you have to give your program, like
file system paths
server names
ports
Jython provides a really nice way of injecting those variables by putting them in a script. It works equally well for injecting java dependencies, as well.
WebSphere and WebLogic use it as their default scripting engine for administrative purposes.
A lot of other Oracle products ship it as part of their "oracle_commons" module (Oracle Universal Installer, Oracle HTTP Server etc). It's mostly version 2.2 being deployed though, which is a bit old and clunky.
There is a list of application that uses jython at http://wiki.python.org/jython/JythonUsers

Can you really use the Visual Studio 2008 IDE to code in Python?

I have a friend who I am trying to teach how to program. He comes from a very basic PHP background, and for some reason is ANTI C#, I guess because some of his PHP circles condemn anything that comes from Microsoft.
Anyways - I've told him its possible to use either Ruby or Python with the VS2008 IDE, because I've read somewhere that this is possible.
But I was wondering. Is it really that practical, can you do EVERYTHING with Python in VS2008 that you can do with C# or VB.net.
I guess without starting a debate... I want to know if you're a developer using VS IDE with a language other than VB.net or C#, then please leave an answer with your experience.
If you are (like me) either a VB.net or C# developer, please don't post speculative or subjective answers. This is a serious question, and I don't want it being closed as subjective. ...
Thank you very much.
update
So far we've established that IronPython is the right tool for the job.
Now how practical is it really?
Mono for example runs C# code in Linux, but... ever tried to use it? Not practical at all, lots of code refactoring needs to take place, no support for .net v3.5, etc...
If you want to use Python together with the .NET Common Language Runtime, then you want one of:
Python.NET (extension to vanilla Python that adds .NET support)
IronPython (re-implementation of Python as a .NET language)
Boo (Python-like language that compiles down to C#-equivalent MSIL code)
Using Python in Visual Studio without using the CLR seems like a bit of a waste to me. Eclipse with PyDev would be a much better choice.
I find it odd that your friend is against C# but is ok with Visual Studio. There is, after all, an open source development environment for .NET called SharpDevelop. The C# language is a standard. .NET is free (as in beer) and there is an open source implementation of that platform called Mono. The only "un-free" thing is Visual Studio (though there are "Express" versions which are free as in beer).
This has been discussed before in this thread. I personally prefer eclipse and pyDev.
I don't know why you would want to - perhaps something like IronPython Studio would be a happy medium. But as I said I don't know why you would want to use Visual Studio for Python development when there are much better options available.
Always choose the right tool for the right job - just because you can drive a nail with the butt-end of your cordless drill doesn't mean that you should. Visual Studio was not designed for Python development and as such will not be a perfect environment for developing in it. Please use the list I have linked to choose a more appropriate editor from that list.
As a side note, I am wondering why your PHP friend refuses to use C# (a free, industry standardized language) but is okay using Visual Studio (an expensive, closed-source integrated development environment).
Firstly, there seems to be a question as to whether python (or various implementations) are as 'powerful' as C#. I'm not quite sure what to take powerful to mean, but in my experience of both languages it will be somewhat easier and faster to write a given piece of code in python than in C#. C# is faster than cpython (although if speed is desired, the psyco python module is well worth a look).
Also I would object to your dismissal of Mono. Mono is great on Linux if you write an application for it from scratch. It is not really meant to be a compatibility layer between Windows and Linux (see Wine!), and if you treat it as such you will only be disappointed.
It just seems to me that you are taking the wrong approach. If you want to convince him that not everything Microsoft is evil, and he is adamant about not learning C#, get him to learn Python (or Ruby, or LUA or whatever) until he is competent, and then introduce him to C# and get him to make his own judgement - I'm fairly in favour of open source, and am far from a rabid Microsoft supporter, but I tried C#, and found I quite liked it.
I think that getting him to use python and visual studio in a suboptimal way will turn him against both of them - far from your desired goal!
Go here for a discussion on the Visual Studio IronPython IDEs.

Study Objective-C , Ruby OR Python? [closed]

Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 9 years ago.
Improve this question
I am working on C++ since last 4-5 years . Recently I have bought iphone and macbook and want do do some programming for iphone.
So I have started reading one book about Objective-C. I have also learn that we can program with Ruby and Python on MAC.
So my question is which one to study? Which language you guys see the FUTURE???
Can we program with these languages on other platforms? Or are these only limited on MAC?
I am just a beginner in objective-C.Need some expert thoughts which way to go.
AC
If you want to program for iphone then you should use objective-C. The entire iphone API is based on objective-C, and you have the benefits of using interface builder and IDE support from Xcode.
I use all the languages C++, Ruby, Python and Objective-C. I like each one in different ways. If you want to get into Mac and iPhone development as others I recommend Objective-C.
One of the benefits not mentioned is that Objective-C is a proper superset of C (C++ is almost a superset), that means you can bring over all your C programming knowledge from doing C++ to Objective-C programming. In fact you can also mix in C++ code in Objective-C code.
You can't do that in a seamless way in Python and Ruby. The reason why you can do this is that Objective-C is actually a very simple language.
Originally it was just C with a custom made preprocessor which took statements like this:
[rectangle setX: 10 y: 10 width: 20 height: 20];
and converted it to this before compiling:
objc_msgSend(rectangle, "setX:y:width:height:", 10, 10, 20, 20);
Apart from that Ruby, Python and Objective-C are very similar in their object model at least compared to C++. In C++ classes are created at compile time. In Objective-C, Ruby and Python classes are things created at runtime.
I wrote some stuff on why Obj-C is cool here
Objective-C is the only way to program an iPhone if you want to produce native programs that can be sold in the App Store.
Some of the more advanced concepts in Objective-C are now being added to languages like C# (eg: extension methods in C# v3.0). Learning to think in Objective-C will be useful, the OO model you learn will be applicable to most other languages and environments as an addition to your C++ experience.
Ruby's object model is closer to that of Objective-C than is Python so I suggest also learning Ruby but not until you have your Objective-C skills down solidly.
Note that you can use Objective-C++ and use C++ for all but your GUI code by having .mm suffixes on your files - this works on both iPhone and Mac. Given your C++ experience, that help you be productive.
If you want to program iPhone, don't bother learning the new Objective-C 2.0 memory management but you can still use the Properties model (iPhone effectively has a subset of the Objective-C 2.0 runtime).
Which language you guys see the FUTURE???
Future of what? iPhone development? Objective-C.
Web Services? Python/Ruby in parallel for a while. At least until people start trying to do maintenance on large Ruby applications and get frustrated with it's opacity.
Real-time game engine development? Embedded applications? Future of what?
"Can we program with these languages on other platforms? Or are these only limited on MAC?"
Ruby and Python: Yes. These are designed to run on any platform that supports C.
Objective-C: Yes. It's open source, it's in the GCC, it should work almost anywhere.
Learning a new language is not a zero-sum game. You can learn more than one language; learning Objective-C now does not prevent you from learning Python or Ruby in the future.
As a Perlite, I'm just going to point out that OS X has Perl as well as Python or Ruby.
As far as Perl/Python/Ruby goes, programs are almost completely cross-platform. It is fairly easy to run a Perl/Python/Ruby program on any platform and it works more or less the same. There may be some minor differences, but they're not major.
Objective-C, while not strictly confined to OS X, is only really used in OpenStep-based environments, which generally means OS X and the iPhone. The only Objective-C compiler I know of is gcc, and I imagine you can write Objective-C on Linux, but I don't know if Windows support is very good (if it exists).
As for which is the language of the "future", all 3 (or 4) languages will be used very widely in the future. No one can really predict this kind of thing, and none of the languages are really going to die off (unless Apple switches to a new language as a "standard" for making Mac programs), so you'll be pretty safe with any of them.
My advice: try them all out and see which one you think most suits your style, and learn that one.
As has been noted by others, if you want to program the iPhone, Objective-C is the way to go.
Objective-C is pretty Mac-specific; of course, the Gnu Objective-C compiler is avaialble for other platforms as well, and there is also GnuStep, but I think the main applicability of Objective-C today is for programming Macs and iPhones.
Python and Ruby on the other hand are available on a large number of platforms (including both Windows and many Unix-dialects). Personally, I prefer Python, but I would say both languages are very usable and pretty easy to approach.
Note also that both Python and Ruby have Objective-C bridges available, which allows you to write quite fancy Cococa applications in any of those languages.
If you program with Objective-C, your main goal should be writing Cocoa applications on the Mac. Beyond that, it has little use. Ruby and Python are useful scripting languages, and there are also bridges to write Cocoa applications.
If you want to write apps on the Mac, I would start with Objective-C. There is more support available.
In terms of the future, it seems like a lot of people are jumping on the Ruby bandwagon at the moment. Good luck.
To program on Mac OS X, you really do need a good foundation in Objective-C. The vast majority of documentation will assume Objective-C. Even if you choose to program some applications in some other language, you will be better off having a good understanding of it.
Ruby. With Ruby you will be able to do both web development (Rails/Sinatra/etc.) and very soon program on the MAC/Iphone platform with the Macruby project. Why not get the best of both worlds?
Tommy
Just my two cents...As I'm sure you're aware, Apple and others in the respective communities are doing a lot of work with Ruby and Python, for both Mac and iPhone development. Objective-C will pretty much get you into Apple arenas only these days (though maybe that's not a bad thing;) However, if you are only going to learn one language in the foreseeable future, think about where you will be using it, and what for. Ruby and Python will get you a lot further if you are looking beyond solely Mac desktop and iPhone.
I have written small games, interpreters, and tons of awessome stuff in Ruby. I Wouldn't recommend It to write intensive AI programs for instance, but It's fun to learn and powerful for most applications. Even when I do most of my work in C++ Ruby is my favorite language for subjective reasons.
Objective C as most people said Is a must in iPhone development, and fun if You're enthusiastic about learning languages.
I haven't tried Python, but I hear nothing but good things about It, and PyGames Is quite popular.
I would learn the three ( well...I would skip objective C unless You're curious about getting into iPhone development), the most languages you know, the best professional You will be. As a good professor of mine always said..It's not about being the master in just one language, It's about knowing the pros and cons of each one to choose the right one according to the particular problem You want to solve.
Cheers !
Objective-C is only Mac/iPhone, and I recommend you to learn if you want to develop applications for Mac/iPhone.
Python is everything and it's future, but python more preferable for web development. Python is Google :) Python is web, games, science, graphics, desktop, etc. Also it's very good choice if you are C/C++ developer.
Not sure if i can recommend you to learn Ruby...

Categories