I would like to embed a Python interpreter into my .NET application. I'm aware of IronPython, of course, but I'm specifically interested in PyPy, because of its stackless support and microthreads.
However, while PyPy can be built against the CLI, it looks like that just gives you a standalone Python interpreter a la python.exe. I haven't been able to find any documentation for building something that can actually be embedded inside a .NET host application.
Is there a way to use (stackless) PyPy to run Python scripts from a .NET app, and allow those scripts to interact with CLR objects provided by the host application?
PyPy's CLI backend is not as mature as C backend and also does not integrate as well with .NET libraries. While normal PyPy compiled to C is production ready, I wouldn't call the .NET version production ready. It's also missing the JIT (although some work has been done in this area) and microthreads. Unless someone steps in, IronPython seems to be the only viable option as of now.
No, there's not. CPython had the ability to access .NET libraries using the Python for .NET (see http://pythonnet.github.io/) maintained at github, but aside from IronPython there's never been a way to actually embed a Python interpreter into a .NET application. This was one of its main selling points.
On a related note, IronPython (by default) has a smaller stack size than CPython when it comes to recursion. That is, you must pass a "-X:FullFrames" command-line option to ipy.exe to enable CPython-esque stack frames. Know this isn't as good as PyPy...but it might help:)
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I'm trying to write a quick and dirty little program to poll a WASP-B ANT+ to wifi gateway on windows, using python (the language I'm most familiar with). The WASP-B device has an unpublished UDP protocol that is mixed up with NDA's and so forth, but they have a published .NET library for win32 programming. So ... I googled around a bit and found IronPython and python.NET. If I understand correctly, IronPython is a .NET application or something? Not really what I'm after, I just want to be able to use the "stuff" in the WASP-B's .NET library from within a python program, so I think python.NET is the better option for me.
As far as I can tell, python.NET isn't all that active though - does anyone here know if it's live, if it'll work with current (3.x) python on Windows and if I'm on the right track?
On sourceforge, python.NET hasn't been touched since Jan 2013 :
http://sourceforge.net/projects/pythonnet/
The WASP, for anyone interested :
http://www.npe-inc.com/products/products-wasp.html
If you're looking for a Python variant that plays very well with .NET, then I highly suggest Iron Python: http://ironpython.net/ it is an open-source variant of Python that was integrated with the .NET framework, allowing it to behave similarly to one of the .NET-friendly languages.
As far as being active, the last update was made on May 25, 2014, which is pretty recent. The updates are not frequent, but for the most part there is no need for them, beyond some improvements and fixes. I would suggest giving it a try and see if it works for you. It's hard to answer a question of something being the right thing for the job unless youn give it a try.
IronPython works wells within .NET environments (calling .NET assemblies). If you stay within .NET framework then IronPython is recommended. Note Python 3 port is in progress and the syntax is not supported yet (Jan 2015).
But CPython (main Python implementation) works well with Python.NET both for extending and embedding. The reason for using CPython with Python.NET is if you need libraries that call Python C-API (not supported by IronPython), like Numpy, Scipy, Pandas, Cython, Matplotlib, etc. Python 3 port is here:
http://www.lfd.uci.edu/~gohlke/pythonlibs/
https://github.com/renshawbay/pythonnet/
I am learning Python. My intentions are:
to write a webapp in Python/Django
create an android app (using Jython)
write some python scripts for unix box
I was under (incorrect) impression that because Python has been implemented in Java (Jython) and .NET (IronPython), I could simply write my Python code and run it through either interpreter/compiler.
I thought if I wrote a hello world in CPython and compiled it with Jython, I'd get Java bytecode. If I compliled it with IronPython, I'd get .NET bytecode.
But now it seems like regular Python code won't work with Jython compiler/interpreter. You've to import some fancy Java specific modules. So, that means, I would have to re-write my program for Java using Java modules/libraries.
Any tips on how to write my Python code so that it works everywhere? Web, Unix, Android.
NOTE: I don't want to have to learn Java.
Thanks
print 'Hello, World!'
This works just fine on any Python implementation worthy of the name. So will most other pure-Python code. Where it gets tricky is when using libraries, as Jython and IronPython are missing some standard library modules and don't support C extensions. Dealing with platform-specific code can also present some issues.
If you want your code to be portable, you need to remove as many dependencies as possible from the shared code. The standard library is generally OK (but not complete in either), and pure-Python external modules are generally OK if they only depend on other pure-Python modules.
If you do need to detect them, I believe the canonical checks are:
if os.name == 'java': # Jython
if sys.platform == 'cli': # IronPython
Neither Jython nor IronPython will produce programs that will run without Jython/IronPython being present. In principle it's possible, and it's even possible to compile a subset of Python to pure bytecode; the former requires linking in the Python engine, and the latter would require restricting what parts of Python you could use.
If someone were to provide this for IronPython I wouldn't turn it down, and I doubt the Jython team would either, but I'm not holding my breath. Either option is a lot of work.
Please be more specific about what you are trying to do. What is your regular Python code ? What does not work with it as you expected ?
According to the Jython FAQ, Jython is an implementation of the Python language. The same Python code should produce the same result on Jython or CPython.
I've built a fairly complicated application with PyQt4 and Python, but it is a pain to send to people (and once I do, they have no idea how to run it). Then there are dependencies to wrestle. Ugh.
Anyways, I just learned about Jython, and since virtually everybody has Java installed, it seems like a perfect solution to my problem of distribution of Python scripts. Has anybody actually developed a functional piece of software with Jython, and if it even exists, one with Jambi bindings?
I'm just asking so that I don't go digging for something which doesn't work.
Thanks!
If you did move this application to Jython, you would have to convert the GUI from QT to Jambi.
Jython is the Python language implemented in Java to run on the Java virtual machine. Because it runs on the JVM, Jython apps can use any Java libraries, such as SWING or Jambi.
It is possible that the differences between PyQT and Jambi are very small, but fundamentally, you would not be using QT directly. Instead you would be using Jambi. And if you use any non-standard Python modules you will still have to resolve packaging issues.
If your application uses other Python modules which are implemented in C, then you would also need to replace those with Java libraries. Jython is great at running a lot of pure Python code unchanged, but Jython runs in a Java environment and there are differences in the way some fundamental objects, such as strings, are implemented. Jython uses Java internals, Java's garbage collector, and so on.
There is more info available via this SO question: Migrating from CPython to Jython
I just downloaded the original Python interpreter from Python's site. I just want to learn this language but to start with, I want to write Windows-based standalone applications that are powered by any RDBMS. I want to bundle it like any typical Windows setup.
I searched old posts on SO and found guys suggesting wxPython and py2exe. Apart from that few suggested IronPython since it is powered by .NET.
I want to know whether IronPython is a pure variant of Python or a modified variant. Secondly, what is the actual use of Python? Is it for PHP like thing or like C# (you can either program Windows-based app. or Web.).
IronPython isn't a variant of Python, it is Python. It's an implementation of the Python language based on the .NET framework. So, yes, it is pure Python.
IronPython is caught up to CPython (the implementation you're probably used to) 2.6, so some of the features/changes seen in Python 2.7 or 3.x will not be present in IronPython. Also, the standard library is a bit different (but what you lose is replaced by all that .NET has to offer).
The primary application of IronPython is to script .NET applications written in C# etc., but it can also be used as a standalone. IronPython can also be used to write web applications using the SilverLight framework.
If you need access to .NET features, use IronPython. If you're just trying to make a Windows executable, use py2exe.
Update
For writing basic RDBMS apps, just use CPython (original Python), it's more extensible and faster. Then, you can use a number of tools to make it stand alone on a Windows PC. For now, though, just worry about learning Python (those skills will mostly carry over to IronPython if you choose to switch) and writing your application.
IronPython is an independent Python implementation written in C# as opposed to the original implementation, often referred to as CPython due to it being written in (no surprise) C.
Python is multi-purpose - you can use it to write web apps (often using a framework such as Django or Pylons), GUI apps (as you've mentioned), command-line tools and as a scripting language embedded inside an app written in another language (for instance, the 3D modelling tool Blender can be scripted using Python).
what does "Pure Python" mean? If you're talking about implemented in Python in the same sense that a module may be pure python, then no, and no Python implementation is. If you mean "Compatible with cPython" then yes, code written to cPython will work in IronPython, with a few caveats. The one that's likely to matter most is that the libraries are different, for instance code depending on ctypes or Tkinter won't work. Another difference is that IronPython lags behind cPython by a bit. the very latest version of this writing is 2.6.1, with an Alpha version supporting a few of the 2.7 language features available too.
What do you really need? If you want to learn to program with python, and also want to produce code for windows, you can use IronPython for that, but you can also use cPython and py2exe; both will work equally well for this with only differences in the libraries.
IronPython is an implementation of Python using C#. It's just like the implementation of Python using Java by Jython. You might want to note that IronPython and Jython will always lag behind a little bit in development. However, you do get the benefit of having some libraries that's not available in the standard Python libraries. In IronPython, you will be able to get access to some of the .NET stuff, like System.Drawings and such, though by using these non-standard libraries, it will be harder to port your code to other platforms. For example, you will have to install mono to run apps written in IronPython on Linux (On windows you will need the .NET Framework)
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