为什么我的Selenium代码在Python Shell中可以工作，但不能在文件中工作？

Question

Here's my code:

from selenium import webdriver
browser = webdriver.Firefox()
browser.get('https://mail.yahoo.com')

emailElem = browser.find_element_by_id('login-username')
emailElem.send_keys('myemail@sbcglobal.net')
emailElem.submit()
passwordElem = browser.find_element_by_id('login-passwd')
passwordElem.send_keys('password')
signInLink = browser.find_element_by_id('login-signin')
signInLink.click()

When I type each line individually in the shell, it works fine and I get logged in to my email, however, when I run the script from a file, it crashes on line 8. Error message is "Unable to locate element [id="login-passwd"]. No idea why it works in the shell though. In there, it obviously does find that field. See screenshot below so you can see how it works on the shell (left), but crashes when run from a file (right). Oh and bonus points if you can tell my why using emailElem.submit() works, but using passwordElem.submit() doesn't. I have to find the button and click that link. If I put passwordElem.submit() the page resets and password field becomes blank. No idea why

Answer 1

The script runs faster than pasting each line in the shell - Since the element is created dynamically in the page, when pasting each line you gave enough time for the browser to run the javascript code and generate the element.

When running the script, the line that searches for the element is reached before the element is created, so you get the error.

There are many possible solutions, which usually involve using a selenium wait method , or time.sleep , or a combination of those.