oeqa/sdk/python: clean up Python test

For the same reasons as the runtime Python test, clean up the SDK test.

Also port from Python 2 to Python 3, as that's what is supported now.

(From OE-Core rev: bead742a3ffc0a53162fb0c36610d74a1422e7b3)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/files/test.py

@@ -1,6 +0,0 @@
-import os
-
-os.system('touch /tmp/testfile.python')
-
-a = 9.01e+21 - 9.01e+21 + 0.01
-print("the value of a is %s" % a)

meta/lib/oeqa/sdk/cases/python.py

@@ -1,32 +1,17 @@
-import os
-import shutil
-import unittest
-
-from oeqa.core.utils.path import remove_safe
+import subprocess, unittest
 from oeqa.sdk.case import OESDKTestCase
 
 class PythonTest(OESDKTestCase):
     @classmethod
     def setUpClass(self):
-        if not (self.tc.hasHostPackage("nativesdk-python") or
-                self.tc.hasHostPackage("python-native")):
+        if not (self.tc.hasHostPackage("nativesdk-python3") or
+                self.tc.hasHostPackage("python3-native")):
             raise unittest.SkipTest("No python package in the SDK")
 
-        for f in ['test.py']:
-            shutil.copyfile(os.path.join(self.tc.files_dir, f),
-                   os.path.join(self.tc.sdk_dir, f))
-
-    def test_python_exists(self):
-        self._run('which python')
-
-    def test_python_stdout(self):
-        output = self._run('python %s/test.py' % self.tc.sdk_dir)
-        self.assertEqual(output.strip(), "the value of a is 0.01", msg="Incorrect output: %s" % output)
-
-    def test_python_testfile(self):
-        self._run('ls /tmp/testfile.python')
-
-    @classmethod
-    def tearDownClass(self):
-        remove_safe("%s/test.py" % self.tc.sdk_dir)
-        remove_safe("/tmp/testfile.python")
+    def test_python3(self):
+        try:
+            cmd = "python3 -c \"import codecs; print(codecs.encode('Uryyb, jbeyq', 'rot13'))\""
+            output = self._run(cmd)
+            self.assertEqual(output, "Hello, world\n")
+        except subprocess.CalledProcessError as e:
+            self.fail("Unexpected exit %d (output %s)" % (e.returncode, e.output))