def check_package(self, package, package_dir):
        """Check namespace packages' __init__ for declare_namespace"""
        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,'rbU')
        if f.read() not in 'declare_namespace'.encode():
            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
dataset/ETHPy150Open balanced/status.balancedpayments.com/venv/lib/python2.7/site-packages/distribute-0.6.34-py2.7.egg/setuptools/command/build_py.py/build_py.check_package/swapped operands of `not in`