--- a/viewer.py	Tue May 05 23:28:22 2015 +0800
+++ b/viewer.py	Tue May 05 23:52:12 2015 +0800
@@ -52,7 +52,7 @@
         rev = self.get_argument('rev', 'tip')
         revcount = 120
 
-        return getinfo('first(%s:0, %d)' % (rev, revcount))
+        return getinfo('first({}:0, {})'.format(rev, revcount))
 
     def getresults(self, changesets):
         results = {}
@@ -110,7 +110,7 @@
         revcount = 120
         regex = re.compile(r'^[-\\|/+ ]+([0-9a-f]{40})$')
         template = '{rev}:{node|short} {tags} {date|isodate} {author|user} {desc|firstline|strip}\n  {node}\n\n'
-        revset = 'first(%s:0, %d)' % (rev, revcount)
+        revset = 'first({}:0, {})'.format(rev, revcount)
         cmd = [HG, 'log', '-R', TESTHGREPO, '-G', '-T', template, '-r', revset]
         graph = subprocess.Popen(cmd, stdout=subprocess.PIPE)
         while graph.poll() is None: