old_contents: import yaml
  import json
  import os.path
  from .util import string
  
  class ConfigReader(object):
      def __init__(self, config_file_path):
          self._config = self._read(config_file_path)
  
      def _read(self, config_file_path):
          try:
              _, ext = os.path.splitext(config_file_path)
              with open(config_file_path) as fin:
                  print ext
                  if ext == '.json':
                      data = json.load(fin)
                  else:
                      data = yaml.safe_load(fin)
              return data
          except Exception as e:
              msg = string.indent_lines(str(e))
              raise ReadingError('Could not read config file:\n%s' % msg)
  
      def get_config(self):
          return self._config
  
  class ReadingError(Exception):
      pass
  
new_contents: import yaml
  import json
  import os.path
  from .util import string
  
  class ConfigReader(object):
      def __init__(self, config_file_path):
          self._config = self._read(config_file_path)
  
      def _read(self, config_file_path):
          try:
              _, ext = os.path.splitext(config_file_path)
              with open(config_file_path) as fin:
                  if ext == '.json':
                      data = json.load(fin)
                  else:
                      data = yaml.safe_load(fin)
              return data
          except Exception as e:
              msg = string.indent_lines(str(e))
              raise ReadingError('Could not read config file:\n%s' % msg)
  
      def get_config(self):
          return self._config
  
  class ReadingError(Exception):
      pass
  
subject: Fix compatibility with Python 3