A minimal example for calling the PyPy interpreter from CPython.

cpython2pypy_minimal.py

#!/usr/bin/env python
'''
   A minimal example for calling the PyPy interpreter from CPython.
   Derived from pyinteractive.py.
   
   This only intended to understand what is going on when.
   PyPy triggers arbitary C compiler runs in between ...
'''   
source="print 'Hello World'"

# The shorter way:
#
#from pypy.interpreter import main
#main.run_string(source)

print "### Importing standard object space ###"
from pypy.objspace.std import StdObjSpace

print "### Importing interpreter code ###"
from pypy.interpreter import eval, module

print "### Creating object space ###"
space = StdObjSpace()
w = space.wrap

print "### Starting byte code compilation ###"
w_code = space.builtin.call('compile', w(source), w('<string>'), w('exec'), w(0), w(0))
pycode = space.interp_w(eval.Code, w_code)

print "### Configuring space ###"
mainmodule = module.Module(space, space.wrap('__main__'))
w_globals = mainmodule.w_dict

print "### Running it ###"
retval = pycode.exec_code(space, w_globals, w_globals)