无法在此python代码中找到错误

Question

无法找到试图在python 2.7中运行的driver.find_element_by_css_selector(button).click()中指示的错误

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

chrome_path=r"C:\Users\Bhanwar\Desktop\New folder (2)\chromedriver.exe"
driver =webdriver.Chrome(chrome_path)
driver.get("https://priceraja.com/mobile/pricelist/samsung-mobile-price-list-in-india")
driver.implicitly_wait(10)
i=0
time = 5
by = By.ID
hook = "product-itmes-"  # The id of one item, they seems to be this plus 
                         # the number item that they are
button = '.loadmore'
while i<4:
     element_number = 25*i  # It looks like there are 25 items added each time, and starts at 25
     WebDriverWait(driver, time).
         until(ec.presence_of_element_located(by, hook+str(element_number))
     driver.find_element_by_css_selector(button).click()
     time.sleep(1)  # Makes the page wait for the element to change
     i+=1