code: def enter_api_key(parser=None):
      
      if parser is None:
          parser = SafeConfigParser()
      parser.add_section('flickr')
      global api_key, api_secret
      api_key = raw_input('Enter your API key: ')
      api_secret = raw_input('Enter your API secret: ')
      parser.set('flickr', 'API_KEY', api_key)
      parser.set('flickr', 'API_SECRET', api_secret)
      with open(CONFIG_PATH, 'wb') as f:
          parser.write(f)
docs: Prompt for API key and secret
      Then write them to CONFIG_PATH(Default: ~/.grabflickr.conf)
  
      :param parser: Config parser
      :type parser: SafeConfigParser