--- a/viewer.py	Mon Jul 04 18:06:48 2016 +0800
+++ b/viewer.py	Mon Jul 04 18:27:36 2016 +0800
@@ -5,8 +5,8 @@
 import os
 import re
 import sqlite3
-import subprocess
 from collections import OrderedDict
+from subprocess import check_output, Popen, PIPE
 from urllib import quote_plus
 
 from tornado.escape import xhtml_escape
@@ -25,7 +25,7 @@
 
 
 def getinfo(revset):
-    output = subprocess.check_output([HG, 'log', '-R', TESTHGREPO, '-T', 'json', '-r', revset])
+    output = check_output([HG, 'log', '-R', TESTHGREPO, '-T', 'json', '-r', revset])
     return json.loads(output)
 
 
@@ -152,7 +152,7 @@
         template = '{rev}:{node|short} {tags} {date|isodate} {author|user} {desc|firstline|strip}\n  {node}\n\n'
         revset = 'first({}:0, {})'.format(rev, revcount)
         cmd = [HG, 'log', '-R', TESTHGREPO, '-G', '-T', template, '-r', revset]
-        graph = subprocess.Popen(cmd, stdout=subprocess.PIPE)
+        graph = Popen(cmd, stdout=PIPE)
         while graph.poll() is None:
             line = graph.stdout.readline()
             matches = regex.findall(line)