code: def get_default_language(language_code=None):
      
  
      if not language_code:
          language_code = settings.LANGUAGE_CODE
  
      languages = dict(settings.LANGUAGES).keys()
  
      # first try if there is an exact language
      if language_code in languages:
          return language_code
  
      # otherwise split the language code if possible, so iso3
      language_code = language_code.split("-")[0]
  
      if language_code not in languages:
          raise ImproperlyConfigured("No match in LANGUAGES for LANGUAGE_CODE %s" % settings.LANGUAGE_CODE)
  
      return language_code
docs: Returns default language depending on settings.LANGUAGE_CODE merged with
      best match from settings.LANGUAGES
  
      Returns: language_code
  
      Raises ImproperlyConfigured if no match found