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

utils.py

Index: utils.py
===================================================================
--- a/utils.py
+++ b/utils.py
@@ -31,14 +31,12 @@
 }
 
 
-def ensureJSShell():
+def ensure_jsshell():
     path = os.environ.get('SPIDERMONKEY_BINARY')
     if path and os.path.isfile(path):
         return path
 
-    baseDir = os.path.dirname(__file__)
     system = platform.system()
-
     try:
         build = JSSHELL_SUPPORTED_PLATFORMS[system]
         if isinstance(build, dict):
@@ -48,7 +46,8 @@
             system, platform.machine()
         ))
 
-    shell_dir = os.path.join(baseDir, JSSHELL_DIR + "-" + build)
+    shell_dir = os.path.join(os.path.dirname(__file__),
+                             '{}-{}'.format(JSSHELL_DIR, build))
     if not os.path.exists(shell_dir):
         os.makedirs(shell_dir)
     if system == 'Windows':
@@ -66,7 +65,7 @@
         archive.extractall(shell_dir)
 
     if not os.path.exists(path):
-        raise Exception('Downloaded package didn\'t contain JS shell executable')
+        raise Exception("Downloaded package doesn't contain JS shell")
 
     try:
         os.chmod(path, 0o700)