Fix test cases and corresponding changes in evaluators for Python 2/3 compatibility

15 files changed, 143 insertions, 117 deletions

diff --git a/yaksh/code_evaluator.py b/yaksh/code_evaluator.py
index a55aed3..b4740c0 100644
--- a/yaksh/code_evaluator.py
+++ b/yaksh/code_evaluator.py
@@ -135,6 +135,7 @@ class CodeEvaluator(object):
     def teardown(self):
         # Cancel the signal
         delete_signal_handler()
+        self._change_dir(MY_DIR)
 
     def check_code(self):
         raise NotImplementedError("check_code method not implemented")
@@ -184,7 +185,7 @@ class CodeEvaluator(object):
             proc.kill()
             # Re-raise exception.
             raise
-        return proc, stdout, stderr
+        return proc, stdout.decode('utf-8'), stderr.decode('utf-8')
 
     def _change_dir(self, in_dir):
         if in_dir is not None and isdir(in_dir):
diff --git a/yaksh/cpp_code_evaluator.py b/yaksh/cpp_code_evaluator.py
index 31b84b2..adef658 100644
--- a/yaksh/cpp_code_evaluator.py
+++ b/yaksh/cpp_code_evaluator.py
@@ -19,9 +19,10 @@ class CppCodeEvaluator(CodeEvaluator):
         self.submit_code_path = self.create_submit_code_file('submit.c')
         self.compiled_user_answer = None
         self.compiled_test_code = None
+        self.user_output_path = ""
+        self.ref_output_path = ""
 
     def teardown(self):
-        super(CppCodeEvaluator, self).teardown()
         # Delete the created file.
         os.remove(self.submit_code_path)
         if os.path.exists(self.ref_output_path):
@@ -30,9 +31,11 @@ class CppCodeEvaluator(CodeEvaluator):
             os.remove(self.user_output_path)
         if self.files:
             delete_files(self.files)
+        super(CppCodeEvaluator, self).teardown()
+
 
     def set_file_paths(self):
-        user_output_path = os.getcwd() + '/output'
+        user_output_path = os.getcwd() + '/output_file'
         ref_output_path = os.getcwd() + '/executable'
 
         return user_output_path, ref_output_path
@@ -105,7 +108,6 @@ class CppCodeEvaluator(CodeEvaluator):
         Returns (False, error_msg): If mandatory arguments are not files or
         if the required permissions are not given to the file(s).
         """
-
         success = False
         proc, stdnt_out, stdnt_stderr = self.compiled_user_answer
         stdnt_stderr = self._remove_null_substitute_char(stdnt_stderr)
@@ -126,28 +128,28 @@ class CppCodeEvaluator(CodeEvaluator):
                 if proc.returncode == 0:
                     success, err = True, "Correct answer"
                 else:
-                    err = stdout + "\n" + stderr
+                    err = "{0} \n {1}".format(stdout, stderr)
             else:
                 err = "Error:"
                 try:
                     error_lines = main_err.splitlines()
                     for e in error_lines:
                         if ':' in e:
-                            err = err + "\n" + e.split(":", 1)[1]
+                            err = "{0} \n {1}".format(err, e.split(":", 1)[1])
                         else:
-                            err = err + "\n" + e
+                            err = "{0} \n {1}".format(err, e)
                 except:
-                        err = err + "\n" + main_err
+                        err = "{0} \n {1}".format(err, main_err)
         else:
             err = "Compilation Error:"
             try:
                 error_lines = stdnt_stderr.splitlines()
                 for e in error_lines:
                     if ':' in e:
-                        err = err + "\n" + e.split(":", 1)[1]
+                        err = "{0} \n {1}".format(err, e.split(":", 1)[1])
                     else:
-                        err = err + "\n" + e
+                        err = "{0} \n {1}".format(err, e)
             except:
-                err = err + "\n" + stdnt_stderr
+                err = "{0} \n {1}".format(err, stdnt_stderr)
 
         return success, err
diff --git a/yaksh/cpp_stdio_evaluator.py b/yaksh/cpp_stdio_evaluator.py
index dab3499..64de54d 100644
--- a/yaksh/cpp_stdio_evaluator.py
+++ b/yaksh/cpp_stdio_evaluator.py
@@ -18,13 +18,13 @@ class CppStdioEvaluator(StdIOEvaluator):
         self.submit_code_path = self.create_submit_code_file('main.c')
 
     def teardown(self):
-        super(CppStdioEvaluator, self).teardown()
         os.remove(self.submit_code_path)
         if self.files:
             delete_files(self.files)
+        super(CppStdioEvaluator, self).teardown()
 
     def set_file_paths(self):
-        user_output_path = os.getcwd() + '/output'
+        user_output_path = os.getcwd() + '/output_file'
         ref_output_path = os.getcwd() + '/executable'
         return user_output_path, ref_output_path
 
diff --git a/yaksh/evaluator_tests/test_bash_evaluation.py b/yaksh/evaluator_tests/test_bash_evaluation.py
index 01e248f..7fdff48 100755
--- a/yaksh/evaluator_tests/test_bash_evaluation.py
+++ b/yaksh/evaluator_tests/test_bash_evaluation.py
@@ -1,6 +1,8 @@
 from __future__ import absolute_import
 import unittest
 import os
+import shutil
+import tempfile
 from yaksh.bash_code_evaluator import BashCodeEvaluator
 from yaksh.bash_stdio_evaluator import BashStdioEvaluator
 from yaksh.settings import SERVER_TIMEOUT
@@ -9,15 +11,23 @@ from textwrap import dedent
 
 class BashAssertionEvaluationTestCases(unittest.TestCase):
     def setUp(self):
+        with open('/tmp/test.txt', 'wb') as f:
+            f.write('2'.encode('ascii'))
+        tmp_in_dir_path = tempfile.mkdtemp()
         self.test_case_data = [
             {"test_case": "bash_files/sample.sh,bash_files/sample.args"}
         ]
-        self.in_dir = os.getcwd()
+        tmp_in_dir_path = tempfile.mkdtemp()
+        self.in_dir = tmp_in_dir_path
         self.timeout_msg = ("Code took more than {0} seconds to run. "
             "You probably have an infinite loop in your"
             " code.").format(SERVER_TIMEOUT)
         self.file_paths = None
 
+    def tearDown(self):
+        os.remove('/tmp/test.txt')
+        shutil.rmtree(self.in_dir)
+
     def test_correct_answer(self):
         user_answer = ("#!/bin/bash\n[[ $# -eq 2 ]]"
             " && echo $(( $1 + $2 )) && exit $(( $1 + $2 ))"
@@ -56,7 +66,7 @@ class BashAssertionEvaluationTestCases(unittest.TestCase):
         self.assertEqual(result.get("error"), self.timeout_msg)
 
     def test_file_based_assert(self):
-        self.file_paths = [(os.getcwd()+"/yaksh/test.txt", False)]
+        self.file_paths = [('/tmp/test.txt', False)]
         self.test_case_data = [
             {"test_case": "bash_files/sample1.sh,bash_files/sample1.args"}
         ]
diff --git a/yaksh/evaluator_tests/test_c_cpp_evaluation.py b/yaksh/evaluator_tests/test_c_cpp_evaluation.py
index d57affa..b3551bf 100755
--- a/yaksh/evaluator_tests/test_c_cpp_evaluation.py
+++ b/yaksh/evaluator_tests/test_c_cpp_evaluation.py
@@ -1,6 +1,8 @@
 from __future__ import absolute_import
 import unittest
 import os
+import shutil
+import tempfile
 from yaksh.cpp_code_evaluator import CppCodeEvaluator
 from yaksh.cpp_stdio_evaluator import CppStdioEvaluator
 from yaksh.settings import SERVER_TIMEOUT
@@ -9,13 +11,20 @@ from textwrap import dedent
 
 class CAssertionEvaluationTestCases(unittest.TestCase):
     def setUp(self):
+        with open('/tmp/test.txt', 'wb') as f:
+            f.write('2'.encode('ascii'))
+        tmp_in_dir_path = tempfile.mkdtemp()
         self.test_case_data = [{"test_case": "c_cpp_files/main.cpp"}]
-        self.in_dir = os.getcwd()
+        self.in_dir = tmp_in_dir_path
         self.timeout_msg = ("Code took more than {0} seconds to run. "
             "You probably have an infinite loop in your"
             " code.").format(SERVER_TIMEOUT)
         self.file_paths = None
 
+    def tearDown(self):
+        os.remove('/tmp/test.txt')
+        shutil.rmtree(self.in_dir)
+
     def test_correct_answer(self):
         user_answer = "int add(int a, int b)\n{return a+b;}"
         get_class = CppCodeEvaluator(self.in_dir)
@@ -35,9 +44,10 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
                     'file_paths': self.file_paths
                 }
         result = get_class.evaluate(**kwargs)
+        lines_of_error = len(result.get('error').splitlines())
         self.assertFalse(result.get('success'))
         self.assertIn("Incorrect:", result.get('error'))
-        self.assertTrue(result.get('error').splitlines > 1)
+        self.assertTrue(lines_of_error > 1)
 
     def test_compilation_error(self):
         user_answer = "int add(int a, int b)\n{return a+b}"
@@ -62,7 +72,7 @@ class CAssertionEvaluationTestCases(unittest.TestCase):
         self.assertEqual(result.get("error"), self.timeout_msg)
 
     def test_file_based_assert(self):
-        self.file_paths = [(os.getcwd()+"/yaksh/test.txt", False)]
+        self.file_paths = [('/tmp/test.txt', False)]
         self.test_case_data = [{"test_case": "c_cpp_files/file_data.c"}]
         user_answer = dedent("""
             #include<stdio.h>
@@ -160,9 +170,10 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
+        lines_of_error = len(result.get('error').splitlines())
         self.assertFalse(result.get('success'))
         self.assertIn("Incorrect", result.get('error'))
-        self.assertTrue(result.get('error').splitlines > 1)
+        self.assertTrue(lines_of_error > 1)
 
     def test_error(self):
         user_answer = dedent("""
@@ -281,9 +292,10 @@ class CppStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
+        lines_of_error = len(result.get('error').splitlines())
         self.assertFalse(result.get('success'))
         self.assertIn("Incorrect", result.get('error'))
-        self.assertTrue(result.get('error').splitlines > 1)
+        self.assertTrue(lines_of_error > 1)
 
     def test_cpp_error(self):
         user_answer = dedent("""
diff --git a/yaksh/evaluator_tests/test_java_evaluation.py b/yaksh/evaluator_tests/test_java_evaluation.py
index f94c6d1..a9708e8 100755
--- a/yaksh/evaluator_tests/test_java_evaluation.py
+++ b/yaksh/evaluator_tests/test_java_evaluation.py
@@ -1,6 +1,8 @@
 from __future__ import absolute_import
 import unittest
 import os
+import shutil
+import tempfile
 from yaksh import code_evaluator as evaluator
 from yaksh.java_code_evaluator import JavaCodeEvaluator
 from yaksh.java_stdio_evaluator import JavaStdioEvaluator
@@ -10,10 +12,13 @@ from textwrap import dedent
 
 class JavaAssertionEvaluationTestCases(unittest.TestCase):
     def setUp(self):
+        with open('/tmp/test.txt', 'wb') as f:
+            f.write('2'.encode('ascii'))
+        tmp_in_dir_path = tempfile.mkdtemp()
         self.test_case_data = [
             {"test_case": "java_files/main_square.java"}
         ]
-        self.in_dir = os.getcwd()
+        self.in_dir = tmp_in_dir_path
         evaluator.SERVER_TIMEOUT = 9
         self.timeout_msg = ("Code took more than {0} seconds to run. "
             "You probably have an infinite loop in"
@@ -21,7 +26,8 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
         self.file_paths = None
 
     def tearDown(self):
-        evaluator.SERVER_TIMEOUT = 2
+        os.remove('/tmp/test.txt')
+        shutil.rmtree(self.in_dir)
 
     def test_correct_answer(self):
         user_answer = "class Test {\n\tint square_num(int a) {\n\treturn a*a;\n\t}\n}"
@@ -43,8 +49,10 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
                 }
         result = get_class.evaluate(**kwargs)
         self.assertFalse(result.get('success'))
-        self.assertIn("Incorrect:", result.get('error'))
-        self.assertTrue(result.get('error').splitlines > 1)
+        lines_of_error = len(result.get('error').splitlines())
+        self.assertFalse(result.get('success'))
+        self.assertIn("Incorrect", result.get('error'))
+        self.assertTrue(lines_of_error > 1)
 
     def test_error(self):
         user_answer = "class Test {\n\tint square_num(int a) {\n\treturn a*a"
@@ -69,7 +77,7 @@ class JavaAssertionEvaluationTestCases(unittest.TestCase):
         self.assertEqual(result.get("error"), self.timeout_msg)
 
     def test_file_based_assert(self):
-        self.file_paths = [(os.getcwd()+"/yaksh/test.txt", False)]
+        self.file_paths = [("/tmp/test.txt", False)]
         self.test_case_data = [
             {"test_case": "java_files/read_file.java"}
         ]
@@ -169,9 +177,10 @@ class JavaStdioEvaluationTestCases(unittest.TestCase):
                   'test_case_data': self.test_case_data
                   }
         result = get_class.evaluate(**kwargs)
+        lines_of_error = len(result.get('error').splitlines())
         self.assertFalse(result.get('success'))
         self.assertIn("Incorrect", result.get('error'))
-        self.assertTrue(result.get('error').splitlines > 1)
+        self.assertTrue(lines_of_error > 1)
 
     def test_error(self):
 
diff --git a/yaksh/evaluator_tests/test_python_evaluation.py b/yaksh/evaluator_tests/test_python_evaluation.py
index 6852136..b93aa13 100755
--- a/yaksh/evaluator_tests/test_python_evaluation.py
+++ b/yaksh/evaluator_tests/test_python_evaluation.py
@@ -1,14 +1,23 @@
 from __future__ import absolute_import
+from six.moves import input
 import unittest
 import os
+import tempfile
+import shutil
+from textwrap import dedent
+
+# Local import
 from yaksh.python_assertion_evaluator import PythonAssertionEvaluator
 from yaksh.python_stdio_evaluator import PythonStdioEvaluator
 from yaksh.settings import SERVER_TIMEOUT
-from textwrap import dedent
 
 
 class PythonAssertionEvaluationTestCases(unittest.TestCase):
     def setUp(self):
+        with open('/tmp/test.txt', 'wb') as f:
+            f.write('2'.encode('ascii'))
+        tmp_in_dir_path = tempfile.mkdtemp()
+        self.in_dir = tmp_in_dir_path
         self.test_case_data = [{"test_case": 'assert(add(1,2)==3)'},
                                {"test_case": 'assert(add(-1,2)==1)'},
                                {"test_case":  'assert(add(-1,-2)==-3)'},
@@ -18,6 +27,10 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
                             " your code.").format(SERVER_TIMEOUT)
         self.file_paths = None
 
+    def tearDown(self):
+        os.remove('/tmp/test.txt')
+        shutil.rmtree(self.in_dir)
+
     def test_correct_answer(self):
         # Given
         user_answer = "def add(a,b):\n\treturn a + b"
@@ -160,7 +173,6 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         """)
         recursion_error_msg = ["Traceback",
                                "call",
-                               "RuntimeError",
                                "maximum recursion depth exceeded"
                                ]
         kwargs = {'user_answer': user_answer,
@@ -175,7 +187,6 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
 
         # Then
         self.assertFalse(result.get("success"))
-        self.assertEqual(969, len(err))
         for msg in recursion_error_msg:
             self.assertIn(msg, result.get("error"))
 
@@ -188,7 +199,6 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
         type_error_msg = ["Traceback",
                           "call",
                           "TypeError",
-                          "exactly",
                           "argument"
                           ]
         kwargs = {'user_answer': user_answer,
@@ -239,7 +249,7 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
     def test_file_based_assert(self):
         # Given
         self.test_case_data = [{"test_case": "assert(ans()=='2')"}]
-        self.file_paths = [(os.getcwd()+"/yaksh/test.txt", False)]
+        self.file_paths = [('/tmp/test.txt', False)]
         user_answer = dedent("""
             def ans():
                 with open("test.txt") as f:
@@ -323,65 +333,10 @@ class PythonAssertionEvaluationTestCases(unittest.TestCase):
             self.assertIn(msg, result.get("error"))
 
 
-class PythonStdoutEvaluationTestCases(unittest.TestCase):
-    def setUp(self):
-        self.test_case_data = [{"expected_input": None,
-                                "expected_output": "0 1 1 2 3"
-                                }]
-
-        self.timeout_msg = ("Code took more than {0} seconds to run. "
-                            "You probably have an infinite loop"
-                            " in your code.").format(SERVER_TIMEOUT)
-
-    def test_correct_answer(self):
-        # Given
-        user_answer = "a,b=0,1\nfor i in range(5):\n\tprint a,\n\ta,b=b,a+b"
-        kwargs = {'user_answer': user_answer,
-                  'test_case_data': self.test_case_data,
-                  }
-
-        # When
-        evaluator = PythonStdioEvaluator()
-        result = evaluator.evaluate(**kwargs)
-
-        # Then
-        self.assertEqual(result.get('error'), "Correct answer")
-        self.assertTrue(result.get('success'))
-
-    def test_incorrect_answer(self):
-        # Given
-        user_answer = "a,b=0,1\nfor i in range(5):\n\tprint b,\n\ta,b=b,a+b"
-        kwargs = {'user_answer': user_answer,
-                  'test_case_data': self.test_case_data,
-                  }
-
-        # When
-        evaluator = PythonStdioEvaluator()
-        result = evaluator.evaluate(**kwargs)
-
-        # Then
-        self.assertFalse(result.get('success'))
-        self.assertIn("Incorrect answer", result.get('error'))
-
-    def test_infinite_loop(self):
-        # Given
-        user_answer = "def add(a, b):\n\twhile True:\n\t\tpass\nadd(1,2)"
-        kwargs = {'user_answer': user_answer,
-                  'test_case_data': self.test_case_data
-                  }
-
-        # When
-        evaluator = PythonStdioEvaluator()
-        result = evaluator.evaluate(**kwargs)
-
-        # Then
-        self.assertEqual(result.get('error'), self.timeout_msg)
-        self.assertFalse(result.get('success'))
-
-
 class PythonStdIOEvaluationTestCases(unittest.TestCase):
-
     def setUp(self):
+        with open('/tmp/test.txt', 'wb') as f:
+            f.write('2'.encode('ascii'))
         self.file_paths = None
 
     def test_correct_answer_integer(self):
@@ -390,9 +345,9 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
                                 "expected_output": "3"
                                 }]
         user_answer = dedent("""
-                                a = input()
-                                b = input()
-                                print a+b
+                                a = int(input())
+                                b = int(input())
+                                print(a+b)
                              """
                              )
         kwargs = {'user_answer': user_answer,
@@ -409,13 +364,16 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
 
     def test_correct_answer_list(self):
         # Given
-        self.test_case_data = [{"expected_input": "[1,2,3]\n[5,6,7]",
+        self.test_case_data = [{"expected_input": "1,2,3\n5,6,7",
                                 "expected_output": "[1, 2, 3, 5, 6, 7]"
                                 }]
         user_answer = dedent("""
-                                a = input()
-                                b = input()
-                                print a+b
+                                from six.moves import input
+                                input_a = input()
+                                input_b = input()
+                                a = [int(i) for i in input_a.split(',')]
+                                b = [int(i) for i in input_b.split(',')]
+                                print(a+b)
                              """
                              )
         kwargs = {'user_answer': user_answer,
@@ -432,14 +390,14 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
 
     def test_correct_answer_string(self):
         # Given
-        self.test_case_data = [{"expected_input": """the quick brown fox jumps\
-                                                     over the lazy dog\nthe""",
+        self.test_case_data = [{"expected_input": ("the quick brown fox jumps over the lazy dog\nthe"),
                                 "expected_output": "2"
                                 }]
         user_answer = dedent("""
-                                a = raw_input()
-                                b = raw_input()
-                                print (a.count(b))
+                                from six.moves import input
+                                a = str(input())
+                                b = str(input())
+                                print(a.count(b))
                              """
                              )
         kwargs = {'user_answer': user_answer,
@@ -460,9 +418,9 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
                                 "expected_output": "3"
                                 }]
         user_answer = dedent("""
-                                a = input()
-                                b = input()
-                                print a-b
+                                a = int(input())
+                                b = int(input())
+                                print(a-b)
                              """
                              )
         kwargs = {'user_answer': user_answer,
@@ -480,12 +438,12 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
     def test_file_based_answer(self):
         # Given
         self.test_case_data = [{"expected_input": "", "expected_output": "2"}]
-        self.file_paths = [(os.getcwd()+"/yaksh/test.txt", False)]
+        self.file_paths = [('/tmp/test.txt', False)]
 
         user_answer = dedent("""
                             with open("test.txt") as f:
                                 a = f.read()
-                                print a[0]
+                                print(a[0])
                              """
                              )
         kwargs = {'user_answer': user_answer,
@@ -501,5 +459,26 @@ class PythonStdIOEvaluationTestCases(unittest.TestCase):
         self.assertEqual(result.get('error'), "Correct answer")
         self.assertTrue(result.get('success'))
 
+    def test_infinite_loop(self):
+        # Given
+        test_case_data = [{"expected_input": "1\n2",
+                                "expected_output": "3"
+                                }]
+        timeout_msg = ("Code took more than {0} seconds to run. "
+                            "You probably have an infinite loop in"
+                            " your code.").format(SERVER_TIMEOUT)
+        user_answer = "while True:\n\tpass"
+        kwargs = {'user_answer': user_answer,
+                  'test_case_data': test_case_data
+                  }
+
+        # When
+        evaluator = PythonStdioEvaluator()
+        result = evaluator.evaluate(**kwargs)
+
+        # Then
+        self.assertEqual(result.get('error'), timeout_msg)
+        self.assertFalse(result.get('success'))
+
 if __name__ == '__main__':
     unittest.main()
diff --git a/yaksh/evaluator_tests/test_scilab_evaluation.py b/yaksh/evaluator_tests/test_scilab_evaluation.py
index f1b29dd..0bb7bfd 100644
--- a/yaksh/evaluator_tests/test_scilab_evaluation.py
+++ b/yaksh/evaluator_tests/test_scilab_evaluation.py
@@ -1,19 +1,26 @@
 from __future__ import absolute_import
 import unittest
 import os
+import shutil
+import tempfile
+
 from yaksh import code_evaluator as evaluator
 from yaksh.scilab_code_evaluator import ScilabCodeEvaluator
 from yaksh.settings import SERVER_TIMEOUT
 
 class ScilabEvaluationTestCases(unittest.TestCase):
     def setUp(self):
+        tmp_in_dir_path = tempfile.mkdtemp()
         self.test_case_data = [{"test_case": "scilab_files/test_add.sce"}]
-        self.in_dir = os.getcwd()
+        self.in_dir = tmp_in_dir_path
         self.timeout_msg = ("Code took more than {0} seconds to run. "
                             "You probably have an infinite loop" 
                             " in your code.").format(SERVER_TIMEOUT)
         self.file_paths = None
 
+    def tearDown(self):
+        shutil.rmtree(self.in_dir)
+
     def test_correct_answer(self):
         user_answer = ("funcprot(0)\nfunction[c]=add(a,b)"
                         "\n\tc=a+b;\nendfunction")
@@ -36,7 +43,7 @@ class ScilabEvaluationTestCases(unittest.TestCase):
                 }
         result = get_class.evaluate(**kwargs) 
         self.assertFalse(result.get("success"))
-        self.assertTrue("error" in result.get("error"))
+        self.assertTrue('error' in result.get("error"))
 
 
     def test_incorrect_answer(self):
@@ -48,9 +55,10 @@ class ScilabEvaluationTestCases(unittest.TestCase):
                     'file_paths': self.file_paths
                 }
         result = get_class.evaluate(**kwargs)
+        lines_of_error = len(result.get('error').splitlines())
         self.assertFalse(result.get('success'))
         self.assertIn("Message", result.get('error'))
-        self.assertTrue(result.get('error').splitlines > 1)
+        self.assertTrue(lines_of_error > 1)
 
     def test_infinite_loop(self):
         user_answer = ("funcprot(0)\nfunction[c]=add(a,b)"
diff --git a/yaksh/java_code_evaluator.py b/yaksh/java_code_evaluator.py
index 2e8c0c6..a294b8e 100644
--- a/yaksh/java_code_evaluator.py
+++ b/yaksh/java_code_evaluator.py
@@ -19,9 +19,10 @@ class JavaCodeEvaluator(CodeEvaluator):
         self.submit_code_path = self.create_submit_code_file('Test.java')
         self.compiled_user_answer = None
         self.compiled_test_code = None
+        self.user_output_path = ""
+        self.ref_output_path = ""
 
     def teardown(self):
-        super(JavaCodeEvaluator, self).teardown()
         # Delete the created file.
         os.remove(self.submit_code_path)
         if os.path.exists(self.user_output_path):
@@ -30,6 +31,8 @@ class JavaCodeEvaluator(CodeEvaluator):
             os.remove(self.ref_output_path)
         if self.files:
             delete_files(self.files)
+        super(JavaCodeEvaluator, self).teardown()
+
 
     def get_commands(self, clean_ref_code_path, user_code_directory):
         compile_command = 'javac  {0}'.format(self.submit_code_path),
diff --git a/yaksh/java_stdio_evaluator.py b/yaksh/java_stdio_evaluator.py
index 71768ef..b5a52f3 100644
--- a/yaksh/java_stdio_evaluator.py
+++ b/yaksh/java_stdio_evaluator.py
@@ -18,10 +18,10 @@ class JavaStdioEvaluator(StdIOEvaluator):
         self.submit_code_path = self.create_submit_code_file('Test.java')
 
     def teardown(self):
-        super(JavaStdioEvaluator, self).teardown()
         os.remove(self.submit_code_path)
         if self.files:
             delete_files(self.files)
+        super(JavaStdioEvaluator, self).teardown()
 
     def set_file_paths(self, directory, file_name):
         output_path = "{0}{1}.class".format(directory, file_name)
diff --git a/yaksh/python_assertion_evaluator.py b/yaksh/python_assertion_evaluator.py
index 78154a3..4f159bf 100644
--- a/yaksh/python_assertion_evaluator.py
+++ b/yaksh/python_assertion_evaluator.py
@@ -1,5 +1,6 @@
 #!/usr/bin/env python
 from __future__ import absolute_import
+from six.moves import input
 import sys
 import traceback
 import os
@@ -19,10 +20,10 @@ class PythonAssertionEvaluator(CodeEvaluator):
         self.exec_scope = None
 
     def teardown(self):
-        super(PythonAssertionEvaluator, self).teardown()
         # Delete the created file.
         if self.files:
             delete_files(self.files)
+        super(PythonAssertionEvaluator, self).teardown()
 
     def compile_code(self, user_answer, file_paths, test_case):
         self.files = []
diff --git a/yaksh/python_stdio_evaluator.py b/yaksh/python_stdio_evaluator.py
index 3011179..5f672e2 100644
--- a/yaksh/python_stdio_evaluator.py
+++ b/yaksh/python_stdio_evaluator.py
@@ -32,10 +32,10 @@ class PythonStdioEvaluator(CodeEvaluator):
     """Tests the Python code obtained from Code Server"""
 
     def teardown(self):
-        super(PythonStdioEvaluator, self).teardown()
         # Delete the created file.
         if self.files:
             delete_files(self.files)
+        super(PythonStdioEvaluator, self).teardown()
 
 
     def compile_code(self, user_answer, file_paths, expected_input, expected_output):
diff --git a/yaksh/scilab_code_evaluator.py b/yaksh/scilab_code_evaluator.py
index 011cb69..075bf6b 100644
--- a/yaksh/scilab_code_evaluator.py
+++ b/yaksh/scilab_code_evaluator.py
@@ -20,11 +20,11 @@ class ScilabCodeEvaluator(CodeEvaluator):
             self.create_submit_code_file('function.sci')
 
     def teardown(self):
-        super(ScilabCodeEvaluator, self).teardown()
         # Delete the created file.
         os.remove(self.submit_code_path)
         if self.files:
             delete_files(self.files)
+        super(ScilabCodeEvaluator, self).teardown()
 
     def check_code(self, user_answer, file_paths, test_case):
         self.files = []
diff --git a/yaksh/stdio_evaluator.py b/yaksh/stdio_evaluator.py
index f1def95..b5924ff 100644
--- a/yaksh/stdio_evaluator.py
+++ b/yaksh/stdio_evaluator.py
@@ -15,8 +15,10 @@ 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))
+        encoded_input = '{0}\n'.format(ip).encode('utf-8')
+        user_output_bytes, output_err_bytes = proc.communicate(encoded_input)
+        user_output = user_output_bytes.decode('utf-8')
+        output_err = output_err_bytes.decode('utf-8')
         expected_output = expected_output.replace("\r", "")
         if not expected_input:
             error_msg = "Expected Output is {0} ".\
@@ -31,5 +33,5 @@ class StdIOEvaluator(CodeEvaluator):
                 err = " Incorrect answer\n" + error_msg +\
                       "\n Your output is {0}".format(repr(user_output))
         else:
-            err = "Error:"+"\n"+output_err
+            err = "Error:\n {0}".format(output_err)
         return success, err
diff --git a/yaksh/test.txt b/yaksh/test.txt
deleted file mode 100644
index 0cfbf08..0000000
--- a/yaksh/test.txt
+++ /dev/null
@@ -1 +0,0 @@
-2