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/ip/__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

@@ -39,10 +39,7 @@ setup(
     setup_requires = build_requires,
     install_requires = build_requires,
 
-    namespace_packages=[
-      "bob",
-      "bob.ip",
-    ],
+
 
     ext_modules=[
       Extension("bob.ip.flandmark.version",