diff --git a/tools/po2js.py b/tools/po2js.py
index c53a874..6776399 100755
--- a/tools/po2js.py
+++ b/tools/po2js.py
@@ -1,58 +1,56 @@
 #!/usr/bin/python
-#
-# convert .po to .js
-#
+"""convert .po to .js file."""
 
 import json
 import optparse
 import os
 import polib
 import re
-import string
 import sys
 
 parser = optparse.OptionParser(usage="usage: %prog [options] pofile...")
-parser.add_option("--callback", default="_.setTranslation", dest="callback", help="callback function to call with data")
-parser.add_option("--quiet", action="store_false", default=True, dest="verbose", help="don't print status messages to stdout")
+parser.add_option("--callback", default="_.setTranslation", dest="callback",
+                  help="callback function to call with data")
+parser.add_option("--quiet", action="store_false", default=True,
+                  dest="verbose", help="don't print status messages to stdout")
 
 (options, args) = parser.parse_args()
 
-if args == None or len(args) == 0:
-	print("ERROR: you must specify at least one po file to translate");
-	sys.exit(1)
+if args is None or len(args) == 0:
+    print("ERROR: you must specify at least one po file to translate")
+    sys.exit(1)
 
 paramFix = re.compile("(\\(([0-9])\\))")
 
 for srcfile in args:
 
-	destfile = os.path.splitext(srcfile)[0] + ".js"
-	if options.verbose:
-		print("INFO: converting %s to %s" % (srcfile, destfile))
-	
-	xlate_map = {}
-	
-	po = polib.pofile(srcfile, autodetect_encoding=False, encoding="utf-8", wrapwidth=-1)
-	for entry in po:
-		if entry.obsolete or entry.msgstr == '' or entry.msgstr == entry.msgid:
-			continue
-			
-		xlate_map[entry.msgid] = entry.msgstr;
-			
-	dest = open(destfile, "w")
-	
-	dest.write(options.callback);
-	dest.write("(");
-	
-	encoder = json.JSONEncoder()
-	
-	for part in encoder.iterencode(xlate_map):
-		if part.startswith('"function('):
-			dest.write(part[1:-1]);
-		else:
-			dest.write(part);
-	
-	dest.write(");\n")
-	
-	dest.close()
+    destfile = os.path.splitext(srcfile)[0] + ".js"
+    if options.verbose:
+        print("INFO: converting %s to %s" % (srcfile, destfile))
 
- 
+    xlate_map = {}
+
+    po = polib.pofile(srcfile, autodetect_encoding=False,
+                      encoding="utf-8", wrapwidth=-1)
+    for entry in po:
+        if entry.obsolete or entry.msgstr == '' or entry.msgstr == entry.msgid:
+            continue
+
+        xlate_map[entry.msgid] = entry.msgstr
+
+    dest = open(destfile, "w")
+
+    dest.write(options.callback)
+    dest.write("(")
+
+    encoder = json.JSONEncoder()
+
+    for part in encoder.iterencode(xlate_map):
+        if part.startswith('"function('):
+            dest.write(part[1:-1])
+        else:
+            dest.write(part)
+
+    dest.write(");\n")
+
+    dest.close()