The above will launch ("embed") a Python 2 or Python 1.5 interpreter from within a Python 3 interpreter. If you use `dlmopen` and `LM_ID_NEWLM`, the guest interpreter will have its own linker namespace. In other words, the guest interpreter (and any DSOs it opens) will be totally isolated from the host interpreter.
The above shows the use of `PyRun_SimpleString`. Since `PyRun_String` accepts a `PyObject* globals` and `PyObject* locals`, you could build a very basic bridge in <30 lines of code by using serialisation to copy and convert. (For user-defined classes, you would need something better.)
I've given a many talks about this at various Python and PyData conferences. (I've mentioned it a number of times on HN, both in response to complaints about the Python 2→3 transition and in response to comments like yours suggesting this solution to that problem.)
Though presented as a joke, the approach could be made to work with some effort. I can't speculate on why no one has ever followed-up on it, and I can't speculate on why the Python 2→3 transition has been so difficult for some users. Perhaps in some places, financial or organisational arguments are more influential than technical arguments.
A couple of signatures have changed, but the general approach looks like: https://gist.github.com/dutc/eba9b2f7980f400f6287 or https://gist.github.com/dutc/2866d969d5e9209d501a
The above will launch ("embed") a Python 2 or Python 1.5 interpreter from within a Python 3 interpreter. If you use `dlmopen` and `LM_ID_NEWLM`, the guest interpreter will have its own linker namespace. In other words, the guest interpreter (and any DSOs it opens) will be totally isolated from the host interpreter.
The above shows the use of `PyRun_SimpleString`. Since `PyRun_String` accepts a `PyObject* globals` and `PyObject* locals`, you could build a very basic bridge in <30 lines of code by using serialisation to copy and convert. (For user-defined classes, you would need something better.)
I've given a many talks about this at various Python and PyData conferences. (I've mentioned it a number of times on HN, both in response to complaints about the Python 2→3 transition and in response to comments like yours suggesting this solution to that problem.)
Though presented as a joke, the approach could be made to work with some effort. I can't speculate on why no one has ever followed-up on it, and I can't speculate on why the Python 2→3 transition has been so difficult for some users. Perhaps in some places, financial or organisational arguments are more influential than technical arguments.