[boost] BPL: How to translate from C++ container to tuple, and back

From: Marc Paterno (paterno_at_[hidden])
Date: 2001-02-28 10:39:13

Hello,

Thanks to David Abrahams for this instructions on getting
a C++ vector passed back to Python. I now find that the
next step I need to take is to turn a C++ sequence (vector,
list, deque...) of "things" into a Python container of the
same "things". Assume that Python already knows about
"things" (either their basic, like int, or they're
already wrapped). My questions are:

(1) What is the best Python type to turn them into?

My current best thought is: if the C++ sequence is not
to be modified (no push_back, no assignment to places in
the sequence), then use a tuple. Otherwise, use a list.
My rule of thumb:

  returned C++ sequence const reference -> Python tuple
  returned C++ sequence (copy) -> Python list

I'd appreciate suggestions from people more expert in
Python than I.

(2) What functions do I write to control the conversion?
Sometimes I also want to translate the contained items,
so I think I may need to write the from_python and to_python
functions myself. An example of doing so for a fairly
simple case would be very useful to me (and perhaps others).

thanks,
Marc Paterno