使用 selenium webdriver 无法定位动态元素

Question

I am working on locating the first name box on facebook.com after you click on create an account. The id changes with every refresh so I am having a hard time locating it. The id is always u_somenumber_b. Such as id = u_1_b, u_2_b etc. Here is what I have so far:

from selenium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC

# Open the Firefox browser
driver = webdriver.Chrome()

# Navigate to “http://qatechhub.com
driver.get('http://www.fb.com')

# Check current URL
url = driver.current_url
print(url)
assert url == 'https://www.facebook.com/'
print("URL confirmed")

# Verify that there is a “Create an account” section on the page.
create_account_css_locator = "a[id='u_0_2']"

# create_account_css_locator = "a#u_0_2" Also works here
create_account_element = driver.find_element_by_css_selector(
    create_account_css_locator)
assert create_account_element.text == 'Create New Account'
print("Create an account section confirmed")
create_account_element.click()


# Fill in the text boxes: First Name, Last Name, Mobile Number or email address,
#  “Re-enter mobile number”, new password.
first_name_xpath = "//input[starts-with(@id, 'u_') and contains(@id, '_b')]"
first_name_element = driver.find_element_by_xpath(first_name_xpath)
print(first_name_element)

When I run code it still doesn't recognize my first_name_element. How would I code this to locate this element?

Answer 1

It is always a good idea to use simple locators that uniquely describe the element. If the id attribute changes I suggest using the name attribute instead which is static:

first_name_xpath = "//input[@name='firstname']"

I'm not sure why your xpath failed since you didn't provide the error you get.

Answer 2

Try with "starts with" and "ends with" CSS selector:

a[id^="u_"][id$="_b"]