Improve style of handler code (#134)

Author: brian-brazil

prometheus_client/exposition.py

@@ -2,14 +2,13 @@
 
 from __future__ import unicode_literals
 
+import base64
 import os
 import socket
-import time
 import threading
+import time
 from contextlib import closing
 from wsgiref.simple_server import make_server
-import base64
-import sys
 
 from . import core
 try:
@@ -146,13 +145,9 @@ def handle():
         '''Handler that implements HTTP Basic Auth.
         '''
         if username is not None and password is not None:
-            if sys.version_info >= (3,0):
-                auth_value = bytes('{0}:{1}'.format(username, password), 'utf8')
-                auth_token = str(base64.b64encode(auth_value), 'utf8')
-            else:
-                auth_value = '{0}:{1}'.format(username, password)
-                auth_token = base64.b64encode(auth_value)
-            auth_header = "Basic {0}".format(auth_token)
+            auth_value = '{0}:{1}'.format(username, password).encode('utf-8')
+            auth_token = base64.b64encode(auth_value)
+            auth_header = b'Basic ' + auth_token
             headers.append(['Authorization', auth_header])
         default_handler(url, method, timeout, headers, data)()