Add tests for py(2|3)-cmd

Test: m par_test{,3} py{2,3}-cmd; ./runtest.sh
Change-Id: I4aadd9fc85be4381bd9a0843064ceaa87150b5ee
diff --git a/python/tests/testpkg/pycmd_test.py b/python/tests/testpkg/pycmd_test.py
new file mode 100644
index 0000000..6b8a263
--- /dev/null
+++ b/python/tests/testpkg/pycmd_test.py
@@ -0,0 +1,33 @@
+# Copyright 2018 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import sys
+
+# This file checks the visible python state against expected values when run
+# via the py*-cmd prebuilts
+
+failed = False
+def assert_equal(what, a, b):
+    global failed
+    if a != b:
+        print("Expected %s('%s') == '%s'" % (what, a, b))
+        failed = True
+
+assert_equal("__name__", __name__, "testpkg.pycmd_test")
+assert_equal("basename(__file__)", os.path.basename(__file__), "pycmd_test.py")
+assert_equal("__package__", __package__, "testpkg")
+
+if failed:
+    sys.exit(1)