code: def get_interface_language():
      
  
      # Solves issue #3627
      try:
          locale_language = locale.getdefaultlocale()[0]
      except ValueError:
          locale_language = DEFAULT_LANGUAGE
  
      # Tests expect English as the interface language
      if running_under_pytest():
          locale_language = DEFAULT_LANGUAGE
  
      language = DEFAULT_LANGUAGE
  
      if locale_language is not None:
          spyder_languages = get_available_translations()
          for lang in spyder_languages:
              if locale_language == lang:
                  language = locale_language
                  break
              elif locale_language.startswith(lang) or \
                lang.startswith(locale_language):
                  language = lang
                  break
  
      return language
docs: If Spyder has a translation available for the locale language, it will
      return the version provided by Spyder adjusted for language subdifferences,
      otherwise it will return DEFAULT_LANGUAGE.
  
      Example:
      1.) Spyder provides ('en',  'de', 'fr', 'es' 'hu' and 'pt_BR'), if the
      locale is either 'en_US' or 'en' or 'en_UK', this function will return 'en'
  
      2.) Spyder provides ('en',  'de', 'fr', 'es' 'hu' and 'pt_BR'), if the
      locale is either 'pt' or 'pt_BR', this function will return 'pt_BR'