试图自动从亚马逊购买鞋子

Question

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support.ui import Select
from selenium.webdriver.support.select import Select
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

driver = webdriver.Chrome()
driver.get("https://www.amazon.com/")
driver.find_element_by_partial_link_text("Sign in").click()
driver.find_element_by_name("email").send_keys("** UR EMAILID **")
driver.find_element_by_name("password").send_keys(" ** UR PASSWORD **")
driver.find_element_by_id("signInSubmit").click()
driver.find_element_by_id("twotabsearchtextbox").send_keys("Mens shoes")
driver.find_element_by_css_selector("#nav-search > form > div.nav-right > div > input").click()
driver.find_element_by_partial_link_text("Fashion Sneakers").click()
dropdown = driver.find_element_by_css_selector("#native_dropdown_selected_size_name")  
select = Select(dropdown)
select.select_by_value("4,B01CE7QQPY")
driver.find_element_by_xpath("//*[@id='add-to-cart-button']").click()

我可以登录，去男士鞋子并选择时尚运动鞋，并选择一种特殊尺寸的鞋子。尽管选择了它的尺寸，但我不允许加入购物车。该页面显示“选择左侧的尺寸以添加到购物车”。终端/命令行没有错误，但我无法继续。我添加了屏幕截图，以供参考，如下图所示：

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