__init__.py 文件源码

def get(prop):
    db_type = name()
    modname = 'trytond.backend.%s' % db_type
    if modname not in sys.modules:
        try:
            __import__(modname)
        except ImportError:
            if not pkg_resources:
                raise
            ep, = pkg_resources.iter_entry_points('trytond.backend', db_type)
            mod_path = os.path.join(ep.dist.location,
                *ep.module_name.split('.')[:-1])
            fp, pathname, description = imp.find_module(db_type, [mod_path])
            imp.load_module(modname, fp, pathname, description)
    module = sys.modules[modname]
    return getattr(module, prop)