I have created an objective-C framework that I would like to import and access through a python script. I understand how to import this stuff in Python, but what do i need to do on the obj-c side to make that framework importable?
Thanks
You'll want to use PyObjC, as Chuck said. Specifically, I'd suggest getting the source, which contains a collection of scripts, pyobjc-metadata (here's the readme), that doesn't seem to be included in the default Apple installation, for wrapping a framework, generating the metadata the Python side needs, and so forth.
You can just use PyObjC, which is included in Mac OS X 10.5 and later.
I'm not sure if this particular combination works, but you might be able to use SWIG to create a Python module out of your Objective-C which can then be imported into Python.
Related
I would like to build my project in Scala and then use it in a script in Python for my data hacking (as a module or something like that). I have seen that there are ways to integrate python code into JVM languages with Jython (only Python 2 projects though). What I want to do is the other way around though. I found no information on the net how to do this, but it seems strange that this should not be possible.
General solution -- use some RPC/IPC (sockets, protobuf, whatever).
However, you might want to look at Spark's solution -- how they translate Python code in Scala's APIs (https://www.py4j.org/) .
Recently, scalapy was created to call Python libraries from Scala.
https://github.com/shadaj/scalapy
I have a Delphi Win32 program. I want to "expose" somehow app structures and procedures via Python module. E.g. module my_api must expose public items for my app structures/methods. This module must "sit" in memory only.
Then I want, in the same app, to call Python scripts (using Python dll) which can import my_api and call my app methods.
How to do it.
You're asking for two things here, which often go together.
First, you want to extend the Python interpreter, adding types and functions and so forth that Python code can use.
Second, you want to embed the Python interpreter in your app, so it can run Python scripts (which can use your extension modules).
Assuming you want to use CPython (the usual Python interpreter), the tutorial Extending and Embedding the Python Interpreter is part of the docs.
You may want to look at other options that help make the extending side easier—for example, you can use Cython to write the bridge code in a near-Python language instead of C, or Boost.Python to write it in nice C++ that takes care of most of the boilerplate for you, or SWIG to try to generate it automatically, or ctypes to avoid writing a bridge in the first place. But it's worth learning the underlying mechanism first.
You may have heard of Python 4 Delphi by now, and if you haven't you can look it up here. https://code.google.com/p/python4delphi/. There are quite a few tutorials on the internet e,g http://www.atug.com/andypatterns/pythonDelphiTalk.htm
I just installed Jython 2.5.1. I want to convert my Python file into Java class file and it is instructed on the website to use the jythonc command-line tool but I can't find it. Does anyone know where I could find it?
Basically what i was trying to accomplish is to get my Python code running client-side in a browser and the best way seemed to be by creating an applet using Jython. I don't want to create a desktop application and using Silverlight/IronPython is out of the question. Any other ideas are welcomed.
Cheers!
You can still compile your python-code to class-files:
import compileall;
compileall.compile_dir('Lib'); # to compile yor Lib-Dir
should work with 2.5 jython
i use it to create class-files to put in jars :-)
Jythonc was removed in Jython 2.2 and is no longer supported. The official way to embed Jython code in Java is to create an instance of the interpreter to run the Jython code directly. There is an article on this here.
Personally I preferred the jythonc method and hope it will be reinstated in a future version of Jython, even though it had a number of issues.
Would it be possible to integrate Python (and/or Perl) and Ruby? I've looked at http://www.goto.info.waseda.ac.jp/~fukusima/ruby/python/doc/ and http://code.google.com/p/ruby-perl/ , but they both seem rather outdated.
Has someone generated a Ruby interface for Python's C API?
Edit: Python can be integrated with many other languages according to http://wiki.python.org/moin/IntegratingPythonWithOtherLanguages . However, that list doesn't include Ruby.
My school (Georgia Tech), along with Bryn Mawr and Microsoft Research, are doing a project right now called Pyjama. Basically, it uses the Microsoft DLR to allow you to freely mix Python and Ruby. I haven't tried it, but it sounds pretty cool.
Here's an example from the website. You enter the class in "Python mode". Then it gets compiled, and you run the command in "Ruby mode".
class PythonClass:
def hello(self, value):
print "Python says hello to", value
pc = python_class().new
pc.hello "Ruby"
Which produces "Python says hello to Ruby".
Integrating dynamic languages is one of the goals of the Parrot project. It's a virtual machine that dynamic language compilers target. Once compiled to the same virtual machine, you should be able to used the "object" form in any of the languages no matter the object's source.
The issue at the moment, however, is stabilizing the virtual machine and finishing off the mostly done compilers. However, that's been the state for a long time. :)
You can write extensions for Ruby in C.
So, if Python has a C API, you can write a C extension for Ruby which uses this API.
I know nothing about the Python API or how large of a piece you want to integrate with, but if it is not too big, this could (possibly) give you a way to run Python code from Ruby.
For a research project I wanted to use the fabulous matplotlib that's available for Python. I also found that library that you referred to. However, it doesn't look like something popular and well tested. So I decided to write the script that generated graphs using pure Python and called it from Ruby via popen. That worked very well for me.
It might by possible, but not very practical. It would be significantly easier to port whatever modules you need from one to the other than it would be to embed one of the interpreters within the other.
If you absolutely have to use both languages in a project, your best option would probably the combination of Jython and Jruby, or IronPython and IronRuby. I'm not sure if you could get them to talk to each other, but at the very least you could host them on the same virtual machine.
Another strategy, as used by Facebook, is to expose APIs via Thrift. You define lightweight service APIs and the RPCs are inter-process.
bbum posted an outline of how to do this, but I'm unable to complete the details. Where does the Python code go, and how will my Objective-C code know about it? How would I do it compiling on the command line?
Source here:
Calling Python From Objective-C
I have posted a full explanation of how to do this to my weblog as it is quite a bit longer than something I would post here.
The abstract summary remains the same: use an abstract class to provide the type information necessary to make the C compiler happy and the metadata necessary to make the bridge happy.
Unfortunately the story for using Python via PyObjC from within an Objective-C app is not very good at the moment. py2app which ships with PyObjC can compile loadable bundles (i.e. can be loaded via NSBundle), which seems like the best approach: define an NSObject subclass in python that implements a protocol (obtained via objc.protocolNamed) that you define in Objective-C, then compile this python file into a loadable bundle via py2app (which uses a standard setup.py). Unfortunately, py2app hasn't had much love, especially the plugin (loadable bundle) target, and a serious memory leak was introduced sometime around 10.5 such that any data passed from python to Objective-C from a py2app-compiled bundle leaks. Yuck.
PyObjC manipulates the Objective-C runtime in accordance with the ObjC-related code executed in Python, thus to be able to call python code from Objective-C, the general outline goes like
Write PyObjC wrapper around python code
Execute code declaring PyObjC wrapper to add these definitions to the ObjC runtime
Call PyObjC wrapper from Objective-C. Because it's declared at runtime, the symbols aren't available at compile time, so you'll have to use NSClassFromString et al. to instantiate the class. It's helpful to declare a #protocol with the appropriate methods so that the Objective-C compiler doesn't complain about missing methods.
If you have flexibility, the best option is to use the Cocoa-Python app templates (i.e. create a Python app), and then load your Objective-C code as a loadable bundle from within Python. This takes care of managing the Python interpreter for you.
Otherwise, with the code in main.m of the Cocoa-Python app template, you should be able to create a Python interpreter, execute your PyObjC code and then continue on. Obviously, the interpreter needs to be kept running so that your python code can execute, so you'll likely have to do this from a separate thread. As you can see this can get a little hairy. Better to go with the Python app, as described above.
Keep in mind that PyObjC is not guaranteed to play well with the Objective-C garbage collector, so all of these options require that your Objective-C code not use GC.
Google is your friend. Performing a search on the string "Cocoa Python" quickly turned up PyObjc.