Use a 'with' block to temporarily change the working directory.

changeDir.py

#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

import logging
import os


log = logging.getLogger( __name__ )


class ChangeDir( ) :
  '''
  Using "with ChangeDir( path ):" the enclosed code uses the specified path as the working directory. On exiting the
  'with' block, the working directory is restored to that before entering the 'with' block.
  '''
  def __init__( self, newPath ) :
    self._newPath = newPath
    self._savedPath = os.getcwd( )

    log.info( 'Saving path, ' + repr( self._savedPath ) )


  def __enter__( self ) :
    # Change to the new directory
    os.chdir( self._newPath )
    log.info( 'Changing to path, ' + repr( self._newPath ) )

    return self._newPath

 
  def __exit__( self, exc_type, exc_value, traceback ) :
    if exc_type is not None :
      # An error occured.
      log.error( exc_type, exc_value, traceback )
      return False

    # Restore the path stored at instantiation
    log.info( 'Restoring original saved path, ' + repr( self._savedPath ) )
    os.chdir( self._savedPath )

    return self