Issue 4374 - Made Python code part of jshydra comply with our coding practices

autotest.py

 # This Source Code is subject to the terms of the Mozilla Public License
 # version 2.0 (the "License"). You can obtain a copy of the License at
 # http://mozilla.org/MPL/2.0/.
 
 from __future__ import print_function
 
 import sys
 import os
 import re
 import difflib
 
 import abp_rewrite
 
 
 def run_tests():
-    testDir = os.path.join(os.path.dirname(__file__), 'autotest')
+    test_dir = os.path.join(os.path.dirname(__file__), 'autotest')
     succeed = True
 
-    for file in os.listdir(testDir):
-        if not re.search(r'^test_.*\.js$', file):
+    for filename in os.listdir(test_dir):
+        if not re.search(r'^test_.*\.js$', filename):
             continue
 
-        file = os.path.join(testDir, file)
-        handle = open(file, 'r')
+        filename = os.path.join(test_dir, filename)
         name = None
-        arguments = None
-        for line in handle:
-            match = re.search(r'^//\s*([A-Za-z]+):\s*(.*?)\s*$', line)
-            if match and match.group(1).lower() == 'name':
-                name = match.group(2)
-            elif match and match.group(1).lower() == 'arguments':
-                arguments = match.group(2).split(' ')
-        handle.close()
+        args = None
 
-        if arguments == None:
+        with open(filename, 'r') as file:
+            for line in file:
+                match = re.search(r'^//\s*([A-Za-z]+):\s*(.*?)\s*$', line)
+                if match:
+                    key = match.group(1).lower()
+                    if key == 'name':
+                        name = match.group(2)
+                    elif key == 'args':
+                        args = match.group(2).split()
+
+        if args is None:
             continue
 
-        output = abp_rewrite.rewrite_js(arguments, file)
-        expected = open(file + '.expected', 'rU').read()
+        output = abp_rewrite.rewrite_js(args, filename)
+        with open(filename + '.expected', 'rU') as file:
+            expected = file.read()
+
         if output == expected:
             print(name + ' passed')
         else:
             succeed = False
             print(name + ' failed! Log:')
             for line in difflib.unified_diff(expected.splitlines(),
                                              output.splitlines(),
-                                             fromfile=file + '.expected',
-                                             tofile=file + '.output'):
+                                             fromfile=filename + '.expected',
+                                             tofile=filename + '.output'):
                 print(line)
             print()
 
     return succeed
 
 if __name__ == '__main__':
     sys.exit(not run_tests())