code: def query_file_location(question, default_address):
  
      
  
      while True:
          if default_address == None:
              prompt = '{}:'.format(question, default_address)
          else:
              prompt = '{} [{}]'.format(question, default_address)
  
          sys.stdout.write(prompt)
          input_address = raw_input()
          if default_address is not None and input_address == '':
              input_address = default_address
          if os.path.isfile(input_address):
              return input_address
          else:
              print 'sorry no file was found at that location\n'
docs: This function asks for a location file address from the command terminal
      it checks if the file exists before proceeding with the code
      "question" is a string that is presented to the user.
      "default_address" is the presumed file location.