Content handler for python.

mojo/tools/data/apptests

 # This file contains a list of Mojo gtest unit tests.
 # This must be a valid python dictionary.
 # TODO(vtl|msw): Add a way of specifying data dependencies.
 [
   {
     "test": "mojo:clipboard_apptests",
   },
   {
     "test": "mojo:example_apptests",
     # ExampleApplicationTest.CheckCommandLineArg checks --example_apptest_arg.
     "test-args": ["--example_apptest_arg"],
   },
   {
     # Runs mojo:example_apptests, replacing the mojo:example_service dependency
     # with the alternate test:example_service, launched via mojo launcher."
     "test": "mojo:example_apptests",
     # ExampleApplicationTest.CheckCommandLineArg checks --example_apptest_arg.
     "test-args": ["--example_apptest_arg"],
     "shell-args": ["--url-mappings=mojo:example_service=test:example_service"],
     "launched-services": ["test:example_service"],
   },
   {
     "test": "mojo:network_service_apptests",
   },
   {
+    "test": "mojo:python_apptests",
+  },
+  {
     "test": "mojo:view_manager_service_apptests",
     "shell-args": ["--args-for=mojo:native_viewport_service --use-headless-config --use-osmesa"],
   },
   {
     "test": "mojo:js_apptests",
   },
 ]