cpy2py 0.12.0

Twinterpreters and TwinMasters

A twinterpreter is simply another interpreter running as a subprocess - with some glue and magic sprinkled on it. You can control and create them using a TwinMaster.

You should only ever worry about two methods: ~TwinMaster.start launches the twinterpreter. ~TwinMaster.execute executes an arbitrary callable in the twinterpreter.

from my_module import my_function
twinterpreter = TwinMaster('pypy')
twinterpreter.start()
twinterpreter.execute(my_function, 1, 2, 3, 'ka-pow!', doctor="who?")

TwinObjects

The real power of cpy2py are Twins - objects living in one twinterpreter and being represented by proxies in any other interpeter. Using twins, you can seamlessly split your application across multiple twins.

You create twins by inheriting from ~cpy2py.proxy.proxy_object.TwinObject instead of object and setting a __twin_id__. That’s it.

from cpy2py import TwinObject
class SuperComputer(TwinObject):
    __twin_id__ = 'pypy'  # makes class native to pypy twinterpeter

    def megaloop(self, x, y):
        return sum(a+b for a in range(x) for b in range(y))

class CWrapper(TwinObject):
    __twin_id__ = 'python'  # makes class native to python twinterpeter

    def callme(self, who, what="buy milk"):
        return some_clib.c_fcn_cll_cplx_xmpl(who, what)

If you don’t set __twin_id__ on a child of ~cpy2py.proxy.proxy_object.TwinObject, the class will always be native to the main interpreter. Handy for all the stuff that’s needed everywhere but really doesn’t belong anywhere.

note:

At the moment, you have to explicitly start a class’s native twinterpreter before instantiating the class. Only the main interpreter is always available, of course.

Debugging

The core of logging facilities. All such loggers are children of the __cpy2py__ logger. By default, no active handlers are attached and propagation is disabled. If needed, you reconfigure them like any other logging logger to suit your needs.

For small scale debugging, one can set the environment variable CPY2PY_DEBUG. If it is defined and not empty, logging output is written to stderr.

Note that loggers are meant for development and only address the internal state. Your application should not depend on this information. Unless cpy2py misbehaves (or you suspect it to), ignore its logging.

Features

• Any pickle’able callable can be dispatched to another interpreter.

• Object functionality is almost fully covered!

  • Objects may reside in any interpreter and transparently interact.

  • Both class and instance attributes work as expected.

  • Methods, classmethods and staticmethods work transparently.

  • Inheritance is fully supported, including multiple inheritance. Affiliation to interpreters can be changed freely.

• A wide range of interpeters is supported.

  • Pure python, no dependencies means perfect portability.

  • Any interpeter compatible with python 2.6 to 3.5 is supported.

  • Virtual Environments work out of the box.

  • Tested with cpython and pypy, on Linux and Mac OSX.

Gotchas/Upcomming

• Calls across interpreters are blocking and not threadsafe.

• Properties and Decorators are not supported yet.

• Module level settings are not synchronized. See issue #7.

• A weakref to objects only takes local references into account, not cross-interpreter references.