Managing large python/c++ project

[mathieu]

Hi there,

  I am currently involved in managing a large python/c++ project
(using swig to automagically wrap c++ code to python). So far my
current experience was that python was a second class citizen and
extremely little python code was written and everything seemed to
work.

  Now this is the contrary, large portion of code are written python
with a few expection of c++ code for core algorithms. So as you might
have guess I am coming with a c++ background into the python world.

  Let's consider the following layout for project 'A':

  A/
    moduleA.py
    B/
      moduleB.py
    C/
      moduleC.py
      module1.cxx
      module1.h
      module1.i
  A-binary-module-gcc43/
    _module1.so
    module1.py

  I have the current questions (I guess it's all about convention):

Q1. How should I import module1 (a c++ module that is compiled/wrap
into python) ? Because I have multiple compilers, I have a binary
directory per compiler. My guess was that PYTHONPATH should contain
the toplevel project *source* directory and the toplevel project
*binary* directory.

Possible answers:
A1.  'import module1'...well in that case I should really make sure
that noone ever tries to create a directory names module1 in directory
A/ otherwise 'import module1' statement is changing meaning.

A2. 'import A-binary-module-gcc43.module1' ... well this is safer and
would avoid namespace collision but the python code becomes dependent
(implicitely) of a compiler.

A3. Leave the module1 where it belong : in A/B/C subdirectory ... in
this case I need to have a source directory per compiler, which means
I need either some subttle trick with symlinks (lndir) or be ready to
have out of sync projects.

Q2. How do I import moduleA & moduleB ? Those are a simple python
modules that are located in A/. Behavior should be symmetric.

A1.
  'from A import moduleA'
  'from A.B import moduleB'

A2.
  'from A import moduleA'
  'from B import moduleB'

A3.
  'import moduleA'
  'import moduleB'

Basically A1 to A3 are organized in complexity of PYTHONPATH. A1 is
great because importing a moduleD in the future will just works
(PYTHONPATH is unchanged). A2 & A3 make the layout of the project
impact on the PYTHONPATH.

Thanks
-Mathieu