While it’s easy to get started with Beautifulsoup, it has limitations when it comes to dynamic websites. That is, websites of which the content changes after each page refresh. Selenium can handle both static and dynamic websites and mimic user behavior (e.g., scrolling, clicking, logging in). It launches another web browser window in which all actions are visible which makes it feel more intuitive. Here we outline the basic commands and installation instructions to get you started.
Finding content in a website’s source code
Running the code snippet below starts a new Google Chrome browser (
driver) and then navigates to the specified URL. In other words, you can follow along with what the computer does behind the screens. Next, you can obtain specific website elements by tag name (e.g.,
h1 is a header) similar to BeautifulSoup.
import selenium.webdriver driver = selenium.webdriver.Chrome() driver.get("https://www.abcdefhijklmnopqrstuvwxyz.nl") # retrieve first H1 header driver.find_element_by_tag_name("h1").text
The first time you will need to:
Install the Python package for Selenium by typing in the command
pip install selenium. Alternatively, open Anaconda Prompt (Windows) or the Terminal (Mac), type the command
conda install selenium, and agree to whatever the package manager wants to install or update (usually by pressing
yto confirm your choice).
Download a web driver to interface with a web browser, we recommend the Webdriver Manager for Python. Install it by typing in the command
pip install webdriver_manager
Configure Selenium to recognize your web driver:
# Make selenium and chromedriver work for Untappd.com from selenium import webdriver from selenium.webdriver.chrome.options import Options from webdriver_manager.chrome import ChromeDriverManager #driver = webdriver.Chrome() driver = webdriver.Chrome(ChromeDriverManager().install()) url = "https://untappd.com/" driver.get(url)
Want to run Chromedriver manually? Check our page on Configuring Python for Web Scraping
Alternatively, you can specify which elements to extract through attributes, classes and identifiers:
# HTML classes driver.find_element_by_class_name("<CLASS_NAME>").text # HTML identifiers () driver.find_element_by_id("<ID_NAME>").text # XPath driver.find_element_by_xpath("<XPATH>").text
Within Google Inspector you can easily obtain the XPath by right-clicking on an element and selecting: “Copy” > “Copy XPath”.
One of the distinguishable features of Selenium is the ability to mimic user interactions which can be vital to get to the data you are after. For example, older tweets are only loaded once you scroll down the page.
# scroll down the page driver.execute_script('window.scrollTo(0, document.body.scrollHeight);') # click on element (e.g., button) element_to_be_clicked = driver.find_element_by_class_name("<CLASS_NAME>") element_to_be_clicked.click()
Advanced Use Case
See the building block on task automation on how to schedule the execution of the web scraper (e.g., every day). Keep in mind that this only works with Python scripts, so if you’re currently working in a Jupyter Notebook you need to transform it into
.py file first.
- Looking for a simple solution that does the job without any bells and whistles? Try out the BeautifulSoup package and review this complementary building block.