Issue2566

jython does support the inspect module in a normal .py file:

$ cat test.py
import inspect

def function():
  frame = inspect.currentframe()
  print inspect.getframeinfo(frame)

function()


$java -jar dist/jython-standalone.jar -c 'import test'
Traceback(filename='test.py', lineno=5, function='function', code_context=['  print inspect.getframeinfo(frame)\n'], index=0)


However if the python module is compiled into bytecode this does not work any more

$ python -m py_compile test.py
$ rm test.py
$ java -jar dist/jython-standalone.jar -c 'import pycimport; import test'

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/home/fwyzard/src/jython/src/dist/Lib/pycimport.py", line 72, in load_module
    return __makeModule( fullname, code, filename )
  File "/home/fwyzard/src/jython/src/dist/Lib/pycimport.py", line 25, in __makeModule
    exec code in module.__dict__
  File "test.py", line 7, in <module>
  File "test.py", line 7, in <module>
  File "test.py", line 5, in function
  File "test.py", line 5, in function
  File "/home/fwyzard/src/jython/src/dist/Lib/inspect.py", line 1015, in getframeinfo
    filename = getsourcefile(frame) or getfile(frame)
  File "/home/fwyzard/src/jython/src/dist/Lib/inspect.py", line 448, in getsourcefile
    filename = getfile(object)
  File "/home/fwyzard/src/jython/src/dist/Lib/inspect.py", line 423, in getfile
    raise TypeError('{!r} is not a module, class, method, '
TypeError: <code object function at 0x2, file "test.py", line 3> is not a module, class, method, function, traceback, frame, or code object


while it still works as expected with the C python interpreter:

$ python2.7 -c 'import test'
Traceback(filename='test.py', lineno=5, function='function', code_context=None, index=None)


The problem seems to be that code objects from a bytecode file are not of type types.CodeType, but of type org.python.core.PyBaseCode (which is its base class).

A possible fix is to change Lib/types.py from

CodeType = type(_f.func_code)

to

CodeType = org.python.core.PyBaseCode

as in the attached patch.

An other possibility would be to change only Lib/inspect.py to explicitly check for org.python.core.PyBaseCode in addition to types.CodeType. The change to Lib/types.py seems more general, though.

After applying the patch and rebuilding jython, this does work

$ java -jar dist/jython-standalone.jar -c 'import pycimport; import test'
Traceback(filename='test.py', lineno=5, function='function', code_context=None, index=None)

Maybe a cleaner approach would be to add
@ExposedType(name="code")
to PyBaseCode (or better even to PyCode..?). However that would require to also add @ExposedField and @ExposedMethod tags to everything that is supposed to be visible on Python side, but I think that's how PyCode subclasses should look anyway. (Was actually surprised that PyCode-stuff doesn't already support the expose mechanism).

In case you try this path, don't forget to add the corresponding classes to CoreExposed.includes file. Otherwise ant won't expose them.

Possibly an easy fix, based on the offered patch, but noting also Stefan's alternative ideas.

However, I suggest we don't rate this as a blocker for 2.7.2.