def check_package(self, package, package_dir):
        try:
            return self.packages_checked[package]
        except KeyError:
            pass

        init_py = _build_py.check_package(self, package, package_dir)
        self.packages_checked[package] = init_py

        if not init_py or not self.distribution.namespace_packages:
            return init_py

        for pkg in self.distribution.namespace_packages:
            if pkg==package or pkg.startswith(package+'.'):
                break
        else:
            return init_py

        f = open(init_py,'rU')
        if 'declare_namespace' not in f.read():
            from distutils import log
            log.warn(
               "WARNING: %s is a namespace package, but its __init__.py does\n"
               "not declare_namespace(); setuptools 0.7 will REQUIRE this!\n"
               '(See the setuptools manual under "Namespace Packages" for '
               "details.)\n", package
            )
        f.close()
        return init_py
Check namespace packages' __init__ for declare_namespace
dataset/ETHPy150Open AppScale/appscale/AppServer/lib/setuptools-0.6c11/setuptools/command/build_py.py/build_py.check_package