[Python-talk] using old .pyc files

[Kent Johnson]

David Betz wrote:
> Thanks for checking into this. I guess there are advantages to being  
> able to change the bytecode definitions from one version to the next.  
> It means you aren't locked into a bad design decision made early on.  
> On the other hand, one of the things I like most about Java is the  
> JVM definition. There is an official documented binary representation  
> of Java programs that is guaranteed to work from version to version.  
> I suppose this started with UCSD Pascal but I really became aware of  
> it with the release of Smalltalk 80. Does anyone know if there has  
> been any effort to standardize a Python virtual machine like the Java  
> virtual machine? Of course, there is a Python->JVM compiler I think  
> but that's not quite the same thing.

The virtual machine and bytecode representation used by CPython are 
considered implementation details, not part of the language definition. 
Jython (compiles to Java VM) and IronPython (compiles to .NET CLR) are 
alternative implementations of the language that do not use the same 
bytecode representation. PyPy is another implementation of the language 
with its own back-end.

Kent