Migrate python code server and evaluators to python 2/3 compatible

22 files changed, 131 insertions, 77 deletions

diff --git a/yaksh/bash_code_evaluator.py b/yaksh/bash_code_evaluator.py
index bce7f07..0cbce89 100644
--- a/yaksh/bash_code_evaluator.py
+++ b/yaksh/bash_code_evaluator.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+from __future__ import absolute_import
 import traceback
 import pwd
 import os
@@ -8,8 +9,8 @@ import subprocess
 import importlib
 
 # local imports
-from code_evaluator import CodeEvaluator
-from file_utils import copy_files, delete_files
+from .code_evaluator import CodeEvaluator
+from .file_utils import copy_files, delete_files
 
 
 class BashCodeEvaluator(CodeEvaluator):
diff --git a/yaksh/bash_stdio_evaluator.py b/yaksh/bash_stdio_evaluator.py
index 8ff0743..fbb94ec 100644
--- a/yaksh/bash_stdio_evaluator.py
+++ b/yaksh/bash_stdio_evaluator.py
@@ -1,11 +1,13 @@
 #!/usr/bin/env python
+from __future__ import absolute_import
 import subprocess
 import os
 from os.path import isfile
 
-# local imports
-from stdio_evaluator import StdIOEvaluator
-from file_utils import copy_files, delete_files
+#local imports
+from .code_evaluator import CodeEvaluator
+from .stdio_evaluator import Evaluator
+from .file_utils import copy_files, delete_files
 
 
 class BashStdioEvaluator(StdIOEvaluator):
diff --git a/yaksh/code_evaluator.py b/yaksh/code_evaluator.py
index 8a9b7a6..a55aed3 100644
--- a/yaksh/code_evaluator.py
+++ b/yaksh/code_evaluator.py
@@ -1,5 +1,6 @@
+#!/usr/bin/env python
+from __future__ import absolute_import
 import sys
-from SimpleXMLRPCServer import SimpleXMLRPCServer
 import pwd
 import os
 import stat
@@ -9,8 +10,15 @@ import traceback
 from multiprocessing import Process, Queue
 import subprocess
 import re
-# Local imports.
-from settings import SERVER_TIMEOUT
+
+try:
+    from SimpleXMLRPCServer import SimpleXMLRPCServer
+except ImportError:
+    # The above import will not work on Python-3.x.
+    from xmlrpc.server import SimpleXMLRPCServer
+
+# Local imports
+from .settings import SERVER_TIMEOUT
 
 MY_DIR = abspath(dirname(__file__))
 
diff --git a/yaksh/code_server.py b/yaksh/code_server.py
index e19e9c8..b753ac7 100755
--- a/yaksh/code_server.py
+++ b/yaksh/code_server.py
@@ -23,7 +23,7 @@ that returns an available server.
 """
 
 # Standard library imports
-from SimpleXMLRPCServer import SimpleXMLRPCServer
+from __future__ import absolute_import
 import json
 from multiprocessing import Process, Queue
 import os
@@ -36,6 +36,12 @@ import subprocess
 import sys
 
 try:
+    from SimpleXMLRPCServer import SimpleXMLRPCServer
+except ImportError:
+    # The above import will not work on Python-3.x.
+    from xmlrpc.server import SimpleXMLRPCServer
+
+try:
     from urllib import unquote
 except ImportError:
     # The above import will not work on Python-3.x.
@@ -45,9 +51,9 @@ except ImportError:
 from tornado.ioloop import IOLoop
 from tornado.web import Application, RequestHandler
 
-# Local imports.
-from settings import SERVER_PORTS, SERVER_POOL_PORT
-from language_registry import create_evaluator_instance, unpack_json
+# Local imports
+from .settings import SERVER_PORTS, SERVER_POOL_PORT
+from .language_registry import create_evaluator_instance, unpack_json
 
 
 MY_DIR = abspath(dirname(__file__))
diff --git a/yaksh/cpp_code_evaluator.py b/yaksh/cpp_code_evaluator.py
index c65242d..31b84b2 100644
--- a/yaksh/cpp_code_evaluator.py
+++ b/yaksh/cpp_code_evaluator.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+from __future__ import absolute_import
 import traceback
 import pwd
 import os
@@ -6,9 +7,9 @@ from os.path import join, isfile
 import subprocess
 import importlib
 
-# local imports
-from code_evaluator import CodeEvaluator
-from file_utils import copy_files, delete_files
+# Local imports
+from .code_evaluator import CodeEvaluator
+from .file_utils import copy_files, delete_files
 
 
 class CppCodeEvaluator(CodeEvaluator):
diff --git a/yaksh/cpp_stdio_evaluator.py b/yaksh/cpp_stdio_evaluator.py
index 720ed0f..dab3499 100644
--- a/yaksh/cpp_stdio_evaluator.py
+++ b/yaksh/cpp_stdio_evaluator.py
@@ -1,12 +1,13 @@
 #!/usr/bin/env python
+from __future__ import absolute_import
 import subprocess
 import os
 from os.path import isfile
 
-#local imports
-
-from stdio_evaluator import StdIOEvaluator
-from file_utils import copy_files, delete_files
+#Local imports
+from .code_evaluator import CodeEvaluator
+from .stdio_evaluator import Evaluator
+from .file_utils import copy_files, delete_files
 
 
 class CppStdioEvaluator(StdIOEvaluator):
diff --git a/yaksh/evaluator_tests/test_bash_evaluation.py b/yaksh/evaluator_tests/test_bash_evaluation.py
index 084e5e4..01e248f 100755
--- a/yaksh/evaluator_tests/test_bash_evaluation.py
+++ b/yaksh/evaluator_tests/test_bash_evaluation.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import unittest
 import os
 from yaksh.bash_code_evaluator import BashCodeEvaluator
@@ -28,7 +29,7 @@ class BashAssertionEvaluationTestCases(unittest.TestCase):
                 }
         result = get_class.evaluate(**kwargs)
         self.assertTrue(result.get('success'))
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct answer")
 
     def test_error(self):
         user_answer = ("#!/bin/bash\n[[ $# -eq 2 ]] "
@@ -52,7 +53,7 @@ class BashAssertionEvaluationTestCases(unittest.TestCase):
                 }
         result = get_class.evaluate(**kwargs)
         self.assertFalse(result.get("success"))
-        self.assertEquals(result.get("error"), self.timeout_msg)
+        self.assertEqual(result.get("error"), self.timeout_msg)
 
     def test_file_based_assert(self):
         self.file_paths = [(os.getcwd()+"/yaksh/test.txt", False)]
@@ -67,7 +68,7 @@ class BashAssertionEvaluationTestCases(unittest.TestCase):
                 }
         result = get_class.evaluate(**kwargs)
         self.assertTrue(result.get("success"))
-        self.assertEquals(result.get("error"), "Correct answer")
+        self.assertEqual(result.get("error"), "Correct answer")
 
 class BashStdioEvaluationTestCases(unittest.TestCase):
     def setUp(self):
@@ -88,7 +89,7 @@ class BashStdioEvaluationTestCases(unittest.TestCase):
                   "test_case_data": test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_array_input(self):
@@ -108,7 +109,7 @@ class BashStdioEvaluationTestCases(unittest.TestCase):
                   "test_case_data": test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_incorrect_answer(self):
@@ -142,7 +143,7 @@ class BashStdioEvaluationTestCases(unittest.TestCase):
                   "test_case_data": test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
 if __name__ == '__main__':
diff --git a/yaksh/evaluator_tests/test_c_cpp_evaluation.py b/yaksh/evaluator_tests/test_c_cpp_evaluation.py
index c6994f6..d57affa 100755
--- a/yaksh/evaluator_tests/test_c_cpp_evaluation.py
+++ b/yaksh/evaluator_tests/test_c_cpp_evaluation.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import unittest
 import os
 from yaksh.cpp_code_evaluator import CppCodeEvaluator
@@ -24,7 +25,7 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
         }
         result = get_class.evaluate(**kwargs)
         self.assertTrue(result.get('success'))
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct answer")
 
     def test_incorrect_answer(self):
         user_answer = "int add(int a, int b)\n{return a-b;}"
@@ -58,7 +59,7 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
                 }
         result = get_class.evaluate(**kwargs)
         self.assertFalse(result.get("success"))
-        self.assertEquals(result.get("error"), self.timeout_msg)
+        self.assertEqual(result.get("error"), self.timeout_msg)
 
     def test_file_based_assert(self):
         self.file_paths = [(os.getcwd()+"/yaksh/test.txt", False)]
@@ -82,7 +83,7 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
                   }
         result = get_class.evaluate(**kwargs)
         self.assertTrue(result.get('success'))
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct answer")
 
 class CppStdioEvaluationTestCases(unittest.TestCase):
 
@@ -106,7 +107,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_array_input(self):
@@ -126,7 +127,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_string_input(self):
@@ -144,7 +145,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_incorrect_answer(self):
@@ -191,7 +192,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   }
         result = get_class.evaluate(**kwargs)
         self.assertFalse(result.get("success"))
-        self.assertEquals(result.get("error"), self.timeout_msg)
+        self.assertEqual(result.get("error"), self.timeout_msg)
 
     def test_only_stdout(self):
         self.test_case_data = [{'expected_output': '11',
@@ -207,7 +208,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_cpp_correct_answer(self):
@@ -224,7 +225,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_cpp_array_input(self):
@@ -245,7 +246,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_cpp_string_input(self):
@@ -264,7 +265,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_cpp_incorrect_answer(self):
@@ -314,7 +315,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   }
         result = get_class.evaluate(**kwargs)
         self.assertFalse(result.get("success"))
-        self.assertEquals(result.get("error"), self.timeout_msg)
+        self.assertEqual(result.get("error"), self.timeout_msg)
 
     def test_cpp_only_stdout(self):
         self.test_case_data = [{'expected_output': '11',
@@ -331,7 +332,7 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
 if __name__ == '__main__':
diff --git a/yaksh/evaluator_tests/test_code_evaluation.py b/yaksh/evaluator_tests/test_code_evaluation.py
index cbca32d..4efe119 100644
--- a/yaksh/evaluator_tests/test_code_evaluation.py
+++ b/yaksh/evaluator_tests/test_code_evaluation.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import unittest
 import os
 from yaksh import python_assertion_evaluator
@@ -38,7 +39,7 @@ class RegistryTestCase(unittest.TestCase):
                 "stdiobasedtestcase": stdout_evaluator_path
             }
         )
-        self.assertEquals(evaluator_class, class_name)
+        self.assertEqual(evaluator_class, class_name)
 
     def tearDown(self):
         self.registry_object = None
diff --git a/yaksh/evaluator_tests/test_java_evaluation.py b/yaksh/evaluator_tests/test_java_evaluation.py
index 60afb3b..f94c6d1 100755
--- a/yaksh/evaluator_tests/test_java_evaluation.py
+++ b/yaksh/evaluator_tests/test_java_evaluation.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import unittest
 import os
 from yaksh import code_evaluator as evaluator
@@ -30,7 +31,7 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
                     'file_paths': self.file_paths
                 }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct answer")
         self.assertTrue(result.get('success'))
 
     def test_incorrect_answer(self):
@@ -65,7 +66,7 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
                 }
         result = get_class.evaluate(**kwargs) 
         self.assertFalse(result.get("success"))
-        self.assertEquals(result.get("error"), self.timeout_msg)
+        self.assertEqual(result.get("error"), self.timeout_msg)
 
     def test_file_based_assert(self):
         self.file_paths = [(os.getcwd()+"/yaksh/test.txt", False)]
@@ -97,7 +98,7 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
                   }
         result = get_class.evaluate(**kwargs)
         self.assertTrue(result.get("success"))
-        self.assertEquals(result.get("error"), "Correct answer")
+        self.assertEqual(result.get("error"), "Correct answer")
 
 class JavaStdioEvaluationTestCases(unittest.TestCase):
 
@@ -127,7 +128,7 @@ class JavaStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_array_input(self):
@@ -149,7 +150,7 @@ class JavaStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_incorrect_answer(self):
@@ -202,7 +203,7 @@ class JavaStdioEvaluationTestCases(unittest.TestCase):
                   }
         result = get_class.evaluate(**kwargs)
         self.assertFalse(result.get("success"))
-        self.assertEquals(result.get("error"), self.timeout_msg)
+        self.assertEqual(result.get("error"), self.timeout_msg)
 
     def test_only_stdout(self):
         self.test_case_data = [{'expected_output': '11',
@@ -219,7 +220,7 @@ class JavaStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
     def test_string_input(self):
@@ -239,7 +240,7 @@ class JavaStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct Answer")
         self.assertTrue(result.get('success'))
 
 if __name__ == '__main__':
diff --git a/yaksh/evaluator_tests/test_python_evaluation.py b/yaksh/evaluator_tests/test_python_evaluation.py
index b72d26b..6852136 100755
--- a/yaksh/evaluator_tests/test_python_evaluation.py
+++ b/yaksh/evaluator_tests/test_python_evaluation.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import unittest
 import os
 from yaksh.python_assertion_evaluator import PythonAssertionEvaluator
diff --git a/yaksh/evaluator_tests/test_scilab_evaluation.py b/yaksh/evaluator_tests/test_scilab_evaluation.py
index f5e3767..f1b29dd 100644
--- a/yaksh/evaluator_tests/test_scilab_evaluation.py
+++ b/yaksh/evaluator_tests/test_scilab_evaluation.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import unittest
 import os
 from yaksh import code_evaluator as evaluator
@@ -22,7 +23,7 @@ class ScilabEvaluationTestCases(unittest.TestCase):
                     'file_paths': self.file_paths
                 }
         result = get_class.evaluate(**kwargs)
-        self.assertEquals(result.get('error'), "Correct answer")
+        self.assertEqual(result.get('error'), "Correct answer")
         self.assertTrue(result.get('success'))
 
     def test_error(self):
@@ -61,7 +62,7 @@ class ScilabEvaluationTestCases(unittest.TestCase):
                 }
         result = get_class.evaluate(**kwargs) 
         self.assertFalse(result.get("success"))
-        self.assertEquals(result.get("error"), self.timeout_msg)
+        self.assertEqual(result.get("error"), self.timeout_msg)
 
 if __name__ == '__main__':
     unittest.main()
diff --git a/yaksh/file_utils.py b/yaksh/file_utils.py
index afcf9e8..82956bf 100644
--- a/yaksh/file_utils.py
+++ b/yaksh/file_utils.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import shutil
 import os
 import zipfile
diff --git a/yaksh/java_code_evaluator.py b/yaksh/java_code_evaluator.py
index ff76317..2e8c0c6 100644
--- a/yaksh/java_code_evaluator.py
+++ b/yaksh/java_code_evaluator.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+from __future__ import absolute_import
 import traceback
 import pwd
 import os
@@ -6,9 +7,9 @@ from os.path import join, isfile
 import subprocess
 import importlib
 
-# local imports
-from code_evaluator import CodeEvaluator
-from file_utils import copy_files, delete_files
+# Local imports
+from .code_evaluator import CodeEvaluator
+from .file_utils import copy_files, delete_files
 
 
 class JavaCodeEvaluator(CodeEvaluator):
diff --git a/yaksh/java_stdio_evaluator.py b/yaksh/java_stdio_evaluator.py
index f4b8773..71768ef 100644
--- a/yaksh/java_stdio_evaluator.py
+++ b/yaksh/java_stdio_evaluator.py
@@ -1,11 +1,13 @@
 #!/usr/bin/env python
+from __future__ import absolute_import
 import subprocess
 import os
 from os.path import isfile
 
-#local imports
-from stdio_evaluator import StdIOEvaluator
-from file_utils import copy_files, delete_files
+#Local imports
+from .code_evaluator import CodeEvaluator
+from .stdio_evaluator import Evaluator
+from .file_utils import copy_files, delete_files
 
 
 class JavaStdioEvaluator(StdIOEvaluator):
diff --git a/yaksh/language_registry.py b/yaksh/language_registry.py
index 398e1aa..5b2b519 100644
--- a/yaksh/language_registry.py
+++ b/yaksh/language_registry.py
@@ -1,6 +1,10 @@
-from settings import code_evaluators
+from __future__ import absolute_import
 import importlib
 import json
+import six  
+
+# Local imports
+from .settings import code_evaluators
 
 registry = None
     
@@ -24,7 +28,7 @@ def create_evaluator_instance(language, test_case_type, json_data, in_dir):
 class _LanguageRegistry(object):
     def __init__(self):
         self._register = {}
-        for language, module in code_evaluators.iteritems():
+        for language, module in six.iteritems(code_evaluators):
             self._register[language] = None
 
     # Public Protocol ##########
diff --git a/yaksh/python_assertion_evaluator.py b/yaksh/python_assertion_evaluator.py
index 1b66fd2..78154a3 100644
--- a/yaksh/python_assertion_evaluator.py
+++ b/yaksh/python_assertion_evaluator.py
@@ -1,13 +1,14 @@
 #!/usr/bin/env python
+from __future__ import absolute_import
 import sys
 import traceback
 import os
 from os.path import join
 import importlib
 
-# local imports
-from code_evaluator import CodeEvaluator, TimeoutException
-from file_utils import copy_files, delete_files
+# Local imports
+from .code_evaluator import CodeEvaluator, TimeoutException
+from .file_utils import copy_files, delete_files
 
 
 class PythonAssertionEvaluator(CodeEvaluator):
@@ -32,7 +33,7 @@ class PythonAssertionEvaluator(CodeEvaluator):
         else:
             submitted = compile(user_answer, '<string>', mode='exec')
             self.exec_scope = {}
-            exec submitted in self.exec_scope
+            exec(submitted, self.exec_scope)
             return self.exec_scope
 
     def check_code(self, user_answer, file_paths, test_case):
@@ -40,7 +41,7 @@ class PythonAssertionEvaluator(CodeEvaluator):
         try:
             tb = None
             _tests = compile(test_case, '<string>', mode='exec')
-            exec _tests in self.exec_scope
+            exec(_tests, self.exec_scope)
         except AssertionError:
             type, value, tb = sys.exc_info()
             info = traceback.extract_tb(tb)
diff --git a/yaksh/python_stdio_evaluator.py b/yaksh/python_stdio_evaluator.py
index 2cfd9c8..3011179 100644
--- a/yaksh/python_stdio_evaluator.py
+++ b/yaksh/python_stdio_evaluator.py
@@ -1,16 +1,23 @@
 #!/usr/bin/env python
+from __future__ import absolute_import
 import sys
 import traceback
 import os
 from os.path import join
 import importlib
 from contextlib import contextmanager
-from ast import literal_eval
-# local imports
-from code_evaluator import CodeEvaluator
-from StringIO import StringIO
-from file_utils import copy_files, delete_files
 from textwrap import dedent
+
+try:
+    from StringIO import StringIO
+except ImportError:
+    from io import StringIO
+
+# Local imports
+from .code_evaluator import CodeEvaluator
+from .file_utils import copy_files, delete_files
+
+
 @contextmanager
 def redirect_stdout():
     new_target = StringIO()
@@ -43,7 +50,7 @@ class PythonStdioEvaluator(CodeEvaluator):
             sys.stdin = input_buffer
         with redirect_stdout() as output_buffer:
             exec_scope = {}
-            exec submitted in exec_scope
+            exec(submitted, exec_scope)
         self.output_value = output_buffer.getvalue().rstrip("\n")
         return self.output_value
 
diff --git a/yaksh/scilab_code_evaluator.py b/yaksh/scilab_code_evaluator.py
index 53fa343..011cb69 100644
--- a/yaksh/scilab_code_evaluator.py
+++ b/yaksh/scilab_code_evaluator.py
@@ -1,4 +1,5 @@
 #!/usr/bin/env python
+from __future__ import absolute_import
 import traceback
 import os
 from os.path import join, isfile
@@ -6,9 +7,9 @@ import subprocess
 import re
 import importlib
 
-# local imports
-from code_evaluator import CodeEvaluator
-from file_utils import copy_files, delete_files
+# Local imports
+from .code_evaluator import CodeEvaluator
+from .file_utils import copy_files, delete_files
 
 
 class ScilabCodeEvaluator(CodeEvaluator):
diff --git a/yaksh/stdio_evaluator.py b/yaksh/stdio_evaluator.py
index efb2ae5..f1def95 100644
--- a/yaksh/stdio_evaluator.py
+++ b/yaksh/stdio_evaluator.py
@@ -15,6 +15,7 @@ class StdIOEvaluator(CodeEvaluator):
     def evaluate_stdio(self, user_answer, proc, expected_input, expected_output):
         success = False
         ip = expected_input.replace(",", " ")
+        print (type(expected_input), type(ip))
         user_output, output_err = proc.communicate(input='{0}\n'.format(ip))
         expected_output = expected_output.replace("\r", "")
         if not expected_input:
diff --git a/yaksh/tests/test_code_server.py b/yaksh/tests/test_code_server.py
index a73f073..1d6584b 100644
--- a/yaksh/tests/test_code_server.py
+++ b/yaksh/tests/test_code_server.py
@@ -1,3 +1,4 @@
+from __future__ import absolute_import
 import json
 try:
     from Queue import Queue
@@ -5,7 +6,7 @@ except ImportError:
     from queue import Queue
 from threading import Thread
 import unittest
-import urllib
+from six.moves import urllib
 
 from yaksh.code_server import ServerPool, SERVER_POOL_PORT
 from yaksh import settings
@@ -18,7 +19,7 @@ class TestCodeServer(unittest.TestCase):
     def setUpClass(cls):
         settings.code_evaluators['python']['standardtestcase'] = \
             "yaksh.python_assertion_evaluator.PythonAssertionEvaluator"
-        ports = range(8001, 8006)
+        ports = range(8001, 8006)   
         server_pool = ServerPool(ports=ports, pool_port=SERVER_POOL_PORT)
         cls.server_pool = server_pool
         cls.server_thread = t = Thread(target=server_pool.run)
@@ -117,7 +118,8 @@ class TestCodeServer(unittest.TestCase):
         url = "http://localhost:%s/status"%SERVER_POOL_PORT
 
         # When
-        data = urllib.urlopen(url).read()
+        response = urllib.request.urlopen(url)
+        data = response.read().decode('utf-8')
 
         # Then
         expect = 'out of 5 are free'
diff --git a/yaksh/xmlrpc_clients.py b/yaksh/xmlrpc_clients.py
index 6bfe0d6..83ba277 100644
--- a/yaksh/xmlrpc_clients.py
+++ b/yaksh/xmlrpc_clients.py
@@ -1,11 +1,19 @@
-from xmlrpclib import ServerProxy
+from __future__ import absolute_import
 import time
 import random
 import socket
 import json
 import urllib
+from six.moves import urllib
 
-from settings import SERVER_PORTS, SERVER_POOL_PORT
+try:
+    from xmlrpclib import ServerProxy
+except ImportError:
+    # The above import will not work on Python-3.x.
+    from xmlrpc.client import ServerProxy
+
+# Local imports
+from .settings import SERVER_PORTS, SERVER_POOL_PORT
 
 
 class ConnectionError(Exception):
@@ -58,7 +66,8 @@ class CodeServerProxy(object):
         return result
 
     def _get_server(self):
-        port = json.loads(urllib.urlopen(self.pool_url).read())
+        response = urllib.request.urlopen(self.pool_url)
+        port = json.loads(response.read().decode('utf-8'))
         proxy = ServerProxy('http://localhost:%d' % port)
         return proxy