How do I fix the TypeError raised when trying to find an element using Selenium?

问题

I am trying to scrape all the links from a web page. I am using Selenium WebDriver to scroll and click the load more button present in the web page. The code which I am trying is as shown below:

from selenium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.common.exceptions import ElementNotVisibleException
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import NoSuchElementException
from bs4 import BeautifulSoup

def fetch_links(url):
    chrome_path = r"D:\nishant_pc_d_drive\nishant_pc\d_drive\update_engine\myntra_update\chromedriver.exe"
    driver = webdriver.Chrome(chrome_path)
    driver.get(url)

    while True:
        try:
            scrollcount=1
            while scrollcount<5:
                driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")
                WebDriverWait(driver, 5)
                scrollcount+=1

            WebDriverWait(driver, 10).until(EC.presence_of_element_located(driver.find_elements_by_css_selector('.load_more .sbt-button, .load_more_order .sbt-button')))
            driver.find_element_by_id("loadmore").click()
        except (ElementNotVisibleException,NoSuchElementException) as e:
            print "done"

    x = driver.page_source
    soup2 = BeautifulSoup(x, 'html.parser')
    linkcount=0
    for each in soup2.find_all('a',attrs={"class":"thumb searchUrlClass"}):
        print "https://www.shoppersstop.com/"+each.get('href')
        linkcount+=1
    print linkcount

# thumb searchUrlClass

fetch_links("https://www.shoppersstop.com/women-westernwear-tops-tees/c-A206020")

But unfortunately it is giving me an error, as shown below:

Traceback (most recent call last):
  File "D:/INVENTORY/shopperstop/fetch_link.py", line 36, in <module>
    fetch_links("https://www.shoppersstop.com/women-westernwear-tops-tees/c-A206020")
  File "D:/INVENTORY/shopperstop/fetch_link.py", line 21, in fetch_links
    WebDriverWait(driver, 10).until(EC.presence_of_element_located(driver.find_element_by_class_name('sbt-button')))
  File "C:\Python27\lib\site-packages\selenium\webdriver\support\wait.py", line 71, in until
    value = method(self._driver)
  File "C:\Python27\lib\site-packages\selenium\webdriver\support\expected_conditions.py", line 63, in __call__
    return _find_element(driver, self.locator)
  File "C:\Python27\lib\site-packages\selenium\webdriver\support\expected_conditions.py", line 328, in _find_element
    return driver.find_element(*by)
TypeError: find_element() argument after * must be an iterable, not WebElement

How can I fix this error? Thanks!

回答1:

from selenium.webdriver.common.by import By

element = WebDriverWait(driver, 10).until(
        EC.presence_of_element_located((By.ID, "myDynamicElement"))
    )

回答2:

The error text is legitimately confusing.

Basically, some EC (Expected Conditions) methods use locators, while some use elements. The one you used only accepts a locator, but you provided an element instead.

The difference is sort of explained in the Selenium API docs here:

element is a WebElement object.
locator is a tuple of (by, path).

Here's a practical example of a locator:

(By.ID, 'someid')

Note: you'll need to import Selenium's "By" class for this.

So, given the initial (bad) code:

WebDriverWait(driver, 10).until(
    EC.presence_of_element_located(driver.find_element_by_class_name('sbt-button'))
)

...it should be updated to:

WebDriverWait(driver, 10).until(
    EC.presence_of_element_located((By.CLASS_NAME, 'sbt-button'))
)

Notice the double parens. That's a tuple being passed to the EC method.

Note: In your case, it also looks like you want multiple elements, so you also need to use EC.presence_of_all_elements_located() instead of EC.presence_of_element_located().

来源：https://stackoverflow.com/questions/43801836/how-do-i-fix-the-typeerror-raised-when-trying-to-find-an-element-using-selenium

标签

python

selenium

selenium-webdriver