selenium change language browser chrome / firefox

Question

I'm trying to test my website with Selenium but I don't manage to change the language of the browser. I tried with Firefox, changing the profile also but it's not working.

That's a pity because much of my content is changing regarding the language.

Here is my Python code:

@classmethod
def setUpClass(cls):
    super(SeleniumTestCase, cls).setUpClass()
    options = Options()
    options.add_argument('--lang=en')
    cls.selenium = WebDriver(chrome_options=options)

So normally I change the language but nothing happens...

Just to clarify. I already checked on stackoverflow and if I post this question it's really because I tried most of the solutions I saw.

Answer 1

FIREFOX JAVA

Java code for changing the language to English:

FirefoxProfile profile = new FirefoxProfile();
profile.setPreference("intl.accept_languages", "en-GB");
FirefoxOptions options = new FirefoxOptions();
options.setProfile(profile);
driver = new FirefoxDriver(options);

CHROME JAVA

Java code for changing the language to English:

ChromeOptions options = new ChromeOptions();
options.addArguments("lang=en-GB");
driver = new ChromeDriver(options);

FIREFOX PYTHON

options = Options()
options.set_preference('intl.accept_languages', 'en-GB')
browser = webdriver.Firefox(options=options)

Answer 2

The answer is already available in one of the very recent post:
Change language on Firefox with Selenium Python

Here is the code:

def get_webdriver(attempts=3, timeout=60, locale='en-us'):
  firefox_profile = webdriver.FirefoxProfile()
  firefox_profile.set_preference("intl.accept_languages", locale)
  firefox_profile.update_preferences()

  desired_capabilities = getattr(
      DesiredCapabilities, "FIREFOX").copy()

  hub_url = urljoin('http://hub:4444', '/wd/hub')
  driver = webdriver.Remote(
    command_executor=hub_url, desired_capabilities=desired_capabilities,
    browser_profile=firefox_profile)

  return driver