Localiser un élement avec sélenium

import selenium
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.common.keys import Keys
import time

driver = webdriver.Firefox()
driver.get('https://www.pagesjaunes.fr/')
inputElems = driver.find_elements( By.ID, "quoiqui" )
for inputElem in inputElems:
  inputElem.send_keys('métallurgie')
  inputElem.send_keys(Keys.ENTER)
time.sleep(4)
inputElemz = driver.find_elements( By.ID, "ou" )
for inputElemt in inputElemz:
  inputElemt.send_keys('Lyon')
  inputElemt.send_keys(Keys.ENTER)
time.sleep(7)
recherche = driver.find_element_by_xpath('//button[@type="submit"]')
recherche.click()
time.sleep(5)
nombre_de_pages = driver.find_element_by_xpath("//strong")
x = nombre_de_pages
#faire une boucle pour répeter le changement de pages
page_suivante = driver.find_element( By.ID, "pagination-next" )
page_suivante.click()
time.sleep(10)
continue_link = driver.find_elements_by_tag_name('a')
elems = driver.find_elements_by_xpath("//*[@href]")
values = [""]
for elem in elems:
    values.append(elem.get_attribute("href"))
print(values)
driver.close()

driver = webdriver.Firefox()
driver.get("https://www.pagesjaunes.fr/annuaire/chercherlespros?quoiqui=m%C3%A9tallurgie&ou=Lyon")
time.sleep(10)
boutton_suivant = driver.find_element_by_tag_name('a')
boutton_suivant_id = driver.find_element(By.ID, "pagination-next")

nombre_de_pages = driver.find_element(with_tag_name('strong').
                                      to_left_of(boutton_suivant_id))
print(nombre_de_pages)
driver.close()

Traceback (most recent call last):
  File "C:/Users/dell/Documents/test2.py", line 26, in <module>
    nombre_de_pages = driver.find_element(with_tag_name('strong').
  File "C:\Users\dell\AppData\Local\Programs\Python\Python39\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 976, in find_element
    return self.execute(Command.FIND_ELEMENT, {
  File "C:\Users\dell\AppData\Local\Programs\Python\Python39\lib\site-packages\selenium\webdriver\remote\webdriver.py", line 319, in execute
    response = self.command_executor.execute(driver_command, params)
  File "C:\Users\dell\AppData\Local\Programs\Python\Python39\lib\site-packages\selenium\webdriver\remote\remote_connection.py", line 372, in execute
    data = utils.dump_json(params)
  File "C:\Users\dell\AppData\Local\Programs\Python\Python39\lib\site-packages\selenium\webdriver\remote\utils.py", line 33, in dump_json
    return json.dumps(json_struct)
  File "C:\Users\dell\AppData\Local\Programs\Python\Python39\lib\json\__init__.py", line 231, in dumps
    return _default_encoder.encode(obj)
  File "C:\Users\dell\AppData\Local\Programs\Python\Python39\lib\json\encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "C:\Users\dell\AppData\Local\Programs\Python\Python39\lib\json\encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "C:\Users\dell\AppData\Local\Programs\Python\Python39\lib\json\encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type RelativeBy is not JSON serializable