diff --git a/resync/url_authority.py b/resync/url_authority.py
index 5163072..2095cb0 100644
--- a/resync/url_authority.py
+++ b/resync/url_authority.py
@@ -1,11 +1,12 @@
 """Determine URI authority based on DNS and paths."""
 
-try: #python3
+try:  # python3
     from urllib.parse import urlparse
-except ImportError: #python2
+except ImportError:  # python2
     from urlparse import urlparse
 import os.path
 
+
 class UrlAuthority(object):
     """Determine URI authority based on DNS and paths.
 
@@ -15,13 +16,13 @@ class UrlAuthority(object):
 
     Two modes are supported:
 
-    strict=True: requires that a query URL has the same URI 
+    strict=True: requires that a query URL has the same URI
     scheme (e.g. http) as the master, is on the same server
     or one in a sub-domain, and that the path component is
     at the same level or below the master.
 
     strict=False (default): requires only that a query URL
-    has the same URI scheme as the master, and is on the same 
+    has the same URI scheme as the master, and is on the same
     server or one in a sub-domain of the master.
 
     Example use:
@@ -42,34 +43,35 @@ class UrlAuthority(object):
         if (self.url is not None):
             self.set_master(self.url)
         else:
-            self.master_scheme='none'
-            self.master_netloc='none.none.none'
-            self.master_path='/not/very/likely'
+            self.master_scheme = 'none'
+            self.master_netloc = 'none.none.none'
+            self.master_path = '/not/very/likely'
 
     def set_master(self, url):
         """Set the master url that this object works with."""
         m = urlparse(url)
-        self.master_scheme=m.scheme
-        self.master_netloc=m.netloc
-        self.master_path=os.path.dirname(m.path)
+        self.master_scheme = m.scheme
+        self.master_netloc = m.netloc
+        self.master_path = os.path.dirname(m.path)
 
     def has_authority_over(self, url):
         """Return True of the current master has authority over url.
 
         In strict mode checks scheme, server and path. Otherwise checks
-        just that the server names match or the query url is a 
-        sub-domain of the master
+        just that the server names match or the query url is a
+        sub-domain of the master.
         """
         s = urlparse(url)
         if (s.scheme != self.master_scheme):
             return(False)
         if (s.netloc != self.master_netloc):
-            if (not s.netloc.endswith('.'+self.master_netloc)):
+            if (not s.netloc.endswith('.' + self.master_netloc)):
                 return(False)
-            #Maybe should allow parallel for 3+ components, eg. a.example.org, b.example.org
+            # Maybe should allow parallel for 3+ components, eg. a.example.org,
+            # b.example.org
         path = os.path.dirname(s.path)
         if (self.strict and
-            path != self.master_path and
-            not path.startswith(self.master_path)):
+                path != self.master_path and
+                not path.startswith(self.master_path)):
             return(False)
         return(True)