make python pep 8 compliant (#159)

native-messaging/app/ping_pong.py

@@ -1,6 +1,8 @@
 #!/usr/bin/env python
+import json
+import struct
+import sys
 
-import sys, json, struct
 
 # Read a message from stdin and decode it.
 def getMessage():
@@ -11,6 +13,7 @@ def getMessage():
     message = sys.stdin.read(messageLength)
     return json.loads(message)
 
+
 # Encode a message for transmission,
 # given its content.
 def encodeMessage(messageContent):
@@ -18,6 +21,7 @@ def encodeMessage(messageContent):
     encodedLength = struct.pack('@I', len(encodedContent))
     return {'length': encodedLength, 'content': encodedContent}
 
+
 # Send an encoded message to stdout
 def sendMessage(encodedMessage):
     sys.stdout.write(encodedMessage['length'])
@@ -26,5 +30,5 @@ def sendMessage(encodedMessage):
 
 while True:
     receivedMessage = getMessage()
-  if (receivedMessage == "ping"):
-    sendMessage(encodeMessage("pong"))
+    if receivedMessage == 'ping':
+        sendMessage(encodeMessage('pong'))