title: Python (flask, babel): detect browser language (NOT preferred/ accepted languages)
body: <p>Before flagging this question as 'duplicate'/ 'already answered', please take into consideration that this 'duplicates' all relate to the ACCEPTED_LANGUAGES headers field.</p>
  
  <p>The question is this: how to detect in Python the language a user has set for his browser's UI? </p>
  
  <p>Using @babel.localeselector returns the language that has the most 'weight' in the browser's language preferred order, not the language of the browser. JS's navigator.language detects the actual language of the browser (except for IE, where navigator.userLanguage returns the OS language, and that only for IE11) - could the same thing be achieved in Python with Flask and Babel? Some other lightweight framework suggestion? Or is my best bet to just stick with the JS path and forget about IE users, and hope their browser language is the same as the OS one?</p>
  
  <p>Thank you</p>