pkg_resources is replaces with pkgutil

bob/__init__.py

-#see http://peak.telecommunity.com/DevCenter/setuptools#namespace-packages
-__import__('pkg_resources').declare_namespace(__name__)
+# see https://docs.python.org/3/library/pkgutil.html
+from pkgutil import extend_path
+__path__ = extend_path(__path__, __name__)

bob/db/__init__.py

-#see http://peak.telecommunity.com/DevCenter/setuptools#namespace-packages
-__import__('pkg_resources').declare_namespace(__name__)
+# see https://docs.python.org/3/library/pkgutil.html
+from pkgutil import extend_path
+__path__ = extend_path(__path__, __name__)

setup.py

@@ -31,10 +31,7 @@ setup(
 
     install_requires = install_requires,
 
-    namespace_packages = [
-      'bob',
-      'bob.db',
-    ],
+
 
     entry_points = {
       # declare database to bob