elems = WebDriverWait(self.driver, 30).until(EC.presence_of_all_elements_located((By.CLASS_NAME, "x")))
print len(elems)
a = len(elems)
self.driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")
time.sleep(4)
elem1 = WebDriverWait(self.driver, 30).until(EC.presence_of_all_elements_located((By.CLASS_NAME, "x")))
b = len(elem1)
while b > a:
    self.driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")
    time.sleep(4)
    elem1 = WebDriverWait(self.driver, 30).until(EC.presence_of_all_elements_located((By.CLASS_NAME, "x")))
    a = b
    b = len(elem1)
print b

prior = 0
while True:
    self.driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")
    current = len(WebDriverWait(self.driver, 30).until(EC.presence_of_all_elements_located((By.CLASS_NAME, "x"))))
    if current == prior:
        return current
    prior = current