Нужно прописать путь до веб браузера .exe :3
gecko = os.path.normpath(os.path.join(os.path.dirname(__file__), 'geckodriver'))
binary = FirefoxBinary(r'C:\Program Files (x86)\Mozilla Firefox\firefox.exe')
driver = webdriver.Firefox(firefox_binary=binary, executable_path=gecko+'.exe')