[Telemetry] Resolve errors due to new pylint checker.

tools/telemetry/telemetry/core/platform/cros_interface.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 """A wrapper around ssh for common operations on a CrOS-based device"""
 import logging
 import re
 import os
 import shutil
 import stat
 import subprocess
@@ skipping 58 matching lines @@
     return False
 
 class LoginException(Exception):
   pass
 
 class KeylessLoginRequiredException(LoginException):
   pass
 
 class CrOSInterface(object):
   # pylint: disable=R0923
-  def __init__(self, hostname = None, ssh_identity = None):
+  def __init__(self, hostname=None, ssh_identity=None):
     self._hostname = hostname
     # List of ports generated from GetRemotePort() that may not be in use yet.
     self._reserved_ports = []
 
     if self.local:
       return
 
     self._ssh_identity = None
     self._ssh_args = ['-o ConnectTimeout=5',
                       '-o StrictHostKeyChecking=no',
@@ skipping 51 matching lines @@
   def _RemoveSSHWarnings(self, toClean):
     """Removes specific ssh warning lines from a string.
 
     Args:
       toClean: A string that may be containing multiple lines.
 
     Returns:
       A copy of toClean with all the Warning lines removed.
     """
     # Remove the Warning about connecting to a new host for the first time.
-    return re.sub('Warning: Permanently added [^\n]* to the list of known '
-                  'hosts.\s\n', '', toClean)
+    return re.sub(
+        r'Warning: Permanently added [^\n]* to the list of known hosts.\s\n',
+        '', toClean)
 
   def RunCmdOnDevice(self, args, cwd=None, quiet=False):
     stdout, stderr = GetAllCmdOutput(
         self.FormSSHCommandLine(args), cwd, quiet=quiet)
     # The initial login will add the host to the hosts file but will also print
     # a warning to stderr that we need to remove.
     stderr = self._RemoveSSHWarnings(stderr)
     return stdout, stderr
 
   def TryLogin(self):
@@ skipping 40 matching lines @@
     return exists
 
   def PushFile(self, filename, remote_filename):
     if self.local:
       args = ['cp', '-r', filename, remote_filename]
       stdout, stderr = GetAllCmdOutput(args, quiet=True)
       if stderr != '':
         raise OSError('No such file or directory %s' % stderr)
       return
 
-    args = ['scp', '-r' ] + self._ssh_args
+    args = ['scp', '-r'] + self._ssh_args
     if self._ssh_identity:
       args.extend(['-i', self._ssh_identity])
 
     args.extend([os.path.abspath(filename),
                  'root@%s:%s' % (self._hostname, remote_filename)])
 
     stdout, stderr = GetAllCmdOutput(args, quiet=True)
     stderr = self._RemoveSSHWarnings(stderr)
     if stderr != '':
       raise OSError('No such file or directory %s' % stderr)
@@ skipping 56 matching lines @@
     """Returns (pid, cmd, ppid, state) of all processes on the device."""
     stdout, stderr = self.RunCmdOnDevice([
         '/bin/ps', '--no-headers',
         '-A',
         '-o', 'pid,ppid,args:4096,state'], quiet=True)
     assert stderr == '', stderr
     procs = []
     for l in stdout.split('\n'): # pylint: disable=E1103
       if l == '':
         continue
-      m = re.match('^\s*(\d+)\s+(\d+)\s+(.+)\s+(.+)', l, re.DOTALL)
+      m = re.match(r'^\s*(\d+)\s+(\d+)\s+(.+)\s+(.+)', l, re.DOTALL)
       assert m
       procs.append((int(m.group(1)), m.group(3).rstrip(),
                     int(m.group(2)), m.group(4)))
     logging.debug("ListProcesses(<predicate>)->[%i processes]" % len(procs))
     return procs
 
   def _GetSessionManagerPid(self, procs):
     """Returns the pid of the session_manager process, given the list of
     processes."""
     for pid, process, _, _ in procs:
@@ skipping 131 matching lines @@
             '/usr/local/autotest/bin/screenshot.py',
             screenshot_file])
         return
     logging.warning('screenshot directory full.')
 
   def RestartUI(self, clear_enterprise_policy):
     logging.info('(Re)starting the ui (logs the user out)')
     if clear_enterprise_policy:
       self.RunCmdOnDevice(['stop', 'ui'])
       self.RmRF('/var/lib/whitelist/*')
-      self.RmRF('/home/chronos/Local\ State')
+      self.RmRF(r'/home/chronos/Local\ State')
 
     if self.IsServiceRunning('ui'):
       self.RunCmdOnDevice(['restart', 'ui'])
     else:
       self.RunCmdOnDevice(['start', 'ui'])
 
   def CloseConnection(self):
     if not self.local:
       with open(os.devnull, 'w') as devnull:
         subprocess.call(self.FormSSHCommandLine(['-O', 'exit', self._hostname]),
                         stdout=devnull, stderr=devnull)