pep-8 and small cleanups
diff --git a/serial/tools/hexlify_codec.py b/serial/tools/hexlify_codec.py
index f3ba04f..5b35e8e 100644
--- a/serial/tools/hexlify_codec.py
+++ b/serial/tools/hexlify_codec.py
@@ -9,18 +9,23 @@
 
 ### Codec APIs
 
+
 def hex_encode(input, errors='strict'):
     return (serial.to_bytes([int(h, 16) for h in input.split()]), len(input))
 
+
 def hex_decode(input, errors='strict'):
     return (''.join('{:02X} '.format(b) for b in input), len(input))
 
+
 class Codec(codecs.Codec):
     def encode(self, input, errors='strict'):
         return serial.to_bytes([int(h, 16) for h in input.split()])
+
     def decode(self, input, errors='strict'):
         return ''.join('{:02X} '.format(b) for b in input)
 
+
 class IncrementalEncoder(codecs.IncrementalEncoder):
 
     def __init__(self, errors='strict'):
@@ -57,18 +62,21 @@
         self.state = state
         return serial.to_bytes(encoded)
 
+
 class IncrementalDecoder(codecs.IncrementalDecoder):
     def decode(self, input, final=False):
         return ''.join('{:02X} '.format(b) for b in input)
 
+
 class StreamWriter(Codec, codecs.StreamWriter):
     pass
 
+
 class StreamReader(Codec, codecs.StreamReader):
     pass
 
-### encodings module API
 
+### encodings module API
 def getregentry():
     return codecs.CodecInfo(
         name='hexlify',