diff --git a/subcmds/__init__.py b/subcmds/__init__.py
index 1fac802..84efb4d 100644
--- a/subcmds/__init__.py
+++ b/subcmds/__init__.py
@@ -38,8 +38,8 @@
     try:
       cmd = getattr(mod, clsn)()
     except AttributeError:
-      raise SyntaxError, '%s/%s does not define class %s' % (
-                         __name__, py, clsn)
+      raise SyntaxError('%s/%s does not define class %s' % (
+                         __name__, py, clsn))
 
     name = name.replace('_', '-')
     cmd.NAME = name
diff --git a/subcmds/branches.py b/subcmds/branches.py
index 06d45ab..c2e7c4b 100644
--- a/subcmds/branches.py
+++ b/subcmds/branches.py
@@ -98,14 +98,13 @@
     project_cnt = len(projects)
 
     for project in projects:
-      for name, b in project.GetBranches().iteritems():
+      for name, b in project.GetBranches().items():
         b.project = project
         if name not in all_branches:
           all_branches[name] = BranchInfo(name)
         all_branches[name].add(b)
 
-    names = all_branches.keys()
-    names.sort()
+    names = list(sorted(all_branches))
 
     if not names:
       print('   (no branches)', file=sys.stderr)
diff --git a/subcmds/help.py b/subcmds/help.py
index 7842882..4aa3f86 100644
--- a/subcmds/help.py
+++ b/subcmds/help.py
@@ -34,8 +34,7 @@
   def _PrintAllCommands(self):
     print('usage: repo COMMAND [ARGS]')
     print('The complete list of recognized repo commands are:')
-    commandNames = self.commands.keys()
-    commandNames.sort()
+    commandNames = list(sorted(self.commands))
 
     maxlen = 0
     for name in commandNames:
@@ -55,10 +54,9 @@
   def _PrintCommonCommands(self):
     print('usage: repo COMMAND [ARGS]')
     print('The most commonly used repo commands are:')
-    commandNames = [name
-                    for name in self.commands.keys()
-                    if self.commands[name].common]
-    commandNames.sort()
+    commandNames = list(sorted([name
+                    for name, command in self.commands.items()
+                    if command.common]))
 
     maxlen = 0
     for name in commandNames:
diff --git a/subcmds/info.py b/subcmds/info.py
index 325874b..c10e56c 100644
--- a/subcmds/info.py
+++ b/subcmds/info.py
@@ -163,7 +163,7 @@
     all_branches = []
     for project in self.GetProjects(args):
       br = [project.GetUploadableBranch(x)
-            for x in project.GetBranches().keys()]
+            for x in project.GetBranches()]
       br = [x for x in br if x]
       if self.opt.current_branch:
         br = [x for x in br if x.name == project.CurrentBranch]
diff --git a/subcmds/overview.py b/subcmds/overview.py
index 418459a..eed8cf2 100644
--- a/subcmds/overview.py
+++ b/subcmds/overview.py
@@ -42,7 +42,7 @@
     all_branches = []
     for project in self.GetProjects(args):
       br = [project.GetUploadableBranch(x)
-            for x in project.GetBranches().keys()]
+            for x in project.GetBranches()]
       br = [x for x in br if x]
       if opt.current_branch:
         br = [x for x in br if x.name == project.CurrentBranch]
diff --git a/subcmds/status.py b/subcmds/status.py
index cce00c8..9810337 100644
--- a/subcmds/status.py
+++ b/subcmds/status.py
@@ -21,10 +21,15 @@
   import dummy_threading as _threading
 
 import glob
+try:
+  # For python2
+  import StringIO as io
+except ImportError:
+  # For python3
+  import io
 import itertools
 import os
 import sys
-import StringIO
 
 from color import Coloring
 
@@ -142,7 +147,7 @@
       for project in all_projects:
         sem.acquire()
 
-        class BufList(StringIO.StringIO):
+        class BufList(io.StringIO):
           def dump(self, ostream):
             for entry in self.buflist:
               ostream.write(entry)
@@ -182,7 +187,7 @@
       try:
         os.chdir(self.manifest.topdir)
 
-        outstring = StringIO.StringIO()
+        outstring = io.StringIO()
         self._FindOrphans(glob.glob('.*') + \
             glob.glob('*'), \
             proj_dirs, proj_dirs_parents, outstring)
diff --git a/subcmds/sync.py b/subcmds/sync.py
index 42c5f91..8fb9488 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -24,8 +24,24 @@
 import subprocess
 import sys
 import time
-import urlparse
-import xmlrpclib
+try:
+  # For python3
+  import urllib.parse
+except ImportError:
+  # For python2
+  import imp
+  import urlparse
+  urllib = imp.new_module('urllib')
+  urllib.parse = urlparse
+try:
+  # For python3
+  import xmlrpc.client
+except ImportError:
+  # For python2
+  import imp
+  import xmlrpclib
+  xmlrpc = imp.new_module('xmlrpc')
+  xmlrpc.client = xmlrpclib
 
 try:
   import threading as _threading
@@ -498,7 +514,7 @@
                   file=sys.stderr)
           else:
             try:
-              parse_result = urlparse.urlparse(manifest_server)
+              parse_result = urllib.parse(manifest_server)
               if parse_result.hostname:
                 username, _account, password = \
                   info.authenticators(parse_result.hostname)
@@ -516,7 +532,7 @@
                                                     1)
 
       try:
-        server = xmlrpclib.Server(manifest_server)
+        server = xmlrpc.client.Server(manifest_server)
         if opt.smart_sync:
           p = self.manifest.manifestProject
           b = p.GetBranch(p.CurrentBranch)
@@ -525,8 +541,7 @@
             branch = branch[len(R_HEADS):]
 
           env = os.environ.copy()
-          if (env.has_key('TARGET_PRODUCT') and
-              env.has_key('TARGET_BUILD_VARIANT')):
+          if 'TARGET_PRODUCT' in env and 'TARGET_BUILD_VARIANT' in env:
             target = '%s-%s' % (env['TARGET_PRODUCT'],
                                 env['TARGET_BUILD_VARIANT'])
             [success, manifest_str] = server.GetApprovedManifest(branch, target)
@@ -554,11 +569,11 @@
         else:
           print('error: %s' % manifest_str, file=sys.stderr)
           sys.exit(1)
-      except (socket.error, IOError, xmlrpclib.Fault) as e:
+      except (socket.error, IOError, xmlrpc.client.Fault) as e:
         print('error: cannot connect to manifest server %s:\n%s'
               % (self.manifest.manifest_server, e), file=sys.stderr)
         sys.exit(1)
-      except xmlrpclib.ProtocolError as e:
+      except xmlrpc.client.ProtocolError as e:
         print('error: cannot connect to manifest server %s:\n%d %s'
               % (self.manifest.manifest_server, e.errcode, e.errmsg),
               file=sys.stderr)
diff --git a/subcmds/upload.py b/subcmds/upload.py
index 48ee685..a34938e 100644
--- a/subcmds/upload.py
+++ b/subcmds/upload.py
@@ -23,6 +23,11 @@
 from error import HookError, UploadError
 from project import RepoHook
 
+try:
+  input = raw_input
+except NameError:
+  pass
+
 UNUSUAL_COMMIT_THRESHOLD = 5
 
 def _ConfirmManyUploads(multiple_branches=False):
@@ -33,7 +38,7 @@
     print('ATTENTION: You are uploading an unusually high number of commits.')
   print('YOU PROBABLY DO NOT MEAN TO DO THIS. (Did you rebase across '
         'branches?)')
-  answer = raw_input("If you are sure you intend to do this, type 'yes': ").strip()
+  answer = input("If you are sure you intend to do this, type 'yes': ").strip()
   return answer == "yes"
 
 def _die(fmt, *args):