PyToolBox

Purpose is to centralize reusable code.

Here is the list of existing modules:

• load_native_module

How to install?

PyToolBox is a standard distutils package. To install it:

$ python setup.py install

How to build the tests?

Use the configure script to reference tools and paths if not defined in standard location: $ ./configure

Documentation available via ./configure --help

Then execute the command make test to build and run tests.

load_native_module

Python prevents loading a module more than once. But sometimes, you really need to deal with several instances of the same module.

with a pure Python module, it's pretty easy:

def load_module(name):
    assert(isinstance(name, str))
    sys.modules.pop(name, None)
    __import__(name)

But when it comes to import native libraries, it's a different story. It turns out a Python module's hash key is the absolute path to that module. So to get n instances of the same module, a workaround is to have n versions of the files on your filesystem in different locations.

This is what this function is doing : each time a new instance of a module is asked, it copies both Python module and its shared library in a fresh temporary directory and load it as a new module.

load_native_library can not load directly the shared library. You need to write an intermediate layer module. If you are using Swig, there is already one.

Usage

from load_native_module import *
with load_native_module('a_swig_generated_module') as m:
    # do stuff
    # [...]
# At this point, the temporary directory is deleted.

Notes

If a module submitted to load_native_module has not been loaded yet, the function uses the `classic' module load. But things will get dirty next time :)

Tests

On linux only:

• Swig 1.3 and Python 2.6
• Swig 2.0.4 and Python 2.7.1