def py_import(module_name, dependency_dictionary, store_in_config=False):
    try:
        result = _vanilla_import(module_name)
        return result
    except ImportError:
        if not getattr(get_vistrails_configuration(), 'installBundles'):
            raise

    if module_name in _previously_failed_pkgs:
        raise PyImportException("Import of Python module '%s' failed again, "
                                "not triggering installation" % module_name)
    if store_in_config:
        ignored_packages_list = getattr(get_vistrails_configuration(),
                                        'bundleDeclinedList',
                                        None)
        if ignored_packages_list:
            ignored_packages = set(ignored_packages_list.split(';'))
        else:
            ignored_packages = set()
        if module_name in ignored_packages:
            raise PyImportException("Import of Python module '%s' failed "
                                    "again, installation disabled by "
                                    "configuration" % module_name)
    debug.warning("Import of python module '%s' failed. "
                  "Will try to install bundle." % module_name)

    success = vistrails.core.bundles.installbundle.install(
            dependency_dictionary)

    if store_in_config:
        if bool(success):
            ignored_packages.discard(module_name)
        else:
            ignored_packages.add(module_name)
        setattr(get_vistrails_configuration(),
                'bundleDeclinedList',
                ';'.join(sorted(ignored_packages)))
        setattr(get_vistrails_persistent_configuration(),
                'bundleDeclinedList',
                ';'.join(sorted(ignored_packages)))

    if not success:
        _previously_failed_pkgs.add(module_name)
        raise PyImportException("Installation of Python module '%s' failed." %
                                module_name)
    try:
        result = _vanilla_import(module_name)
        return result
    except ImportError, e:
        _previously_failed_pkgs.add(module_name)
        raise PyImportBug("Installation of package '%s' succeeded, but import "
                          "still fails." % module_name)
Tries to import a python module, installing if necessary.
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/core/bundles/pyimport.py/py_import