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BeautifulSoup. Others explicitly forbid it. If there are not, then it becomes more of a judgement call. Here are some examples: You can learn more about CSS selectors here. With the children attribute, we can get the children Some websites explicitly allow web scraping. We pass them in as part of a dictionary. We import the BeautifulSoup class from the bs4 attribute also returns spaces between the tags, we add a condition to include That means there are lots of tutorials, how-to videos, and bits of example code out there to help you deepen your knowledge once you’ve mastered the Beautiful Soup basics. Our code would request the site’s content from its server and download it. with the read method. The main content of the web page goes into the body tag. With the prettify method, we can make the HTML code look better. A BeautifulSoup object is created; the HTML data is passed to the If we want to extract a single tag, we can instead use the find_all method, which will find all the instances of a tag on a page. We can use CSS selectors to find all the p tags in our page that are inside of a div like this: Note that the select method above returns a list of BeautifulSoup objects, just like find and find_all. One thing that’s important to note: from a server’s perspective, requesting a page via web scraping is the same as loading it in a web browser. document. You should end up with a panel at the bottom of the browser like what you see below. Many websites don’t offer any clear guidance one way or the other. HTML allows you to do similar things to what you do in a word processor like Microsoft Word — make text bold, create paragraphs, and so on. It provides methods for Because HTML isn’t a programming language, it isn’t nearly as complex as Python. The files fall into a few main types: After our browser receives all the files, it renders the page and displays it to us. By right clicking on the page near where it says “Extended Forecast”, then clicking “Inspect”, we’ll open up the tag that contains the text “Extended Forecast” in the elements panel: We can then scroll up in the elements panel to find the “outermost” element that contains all of the text that corresponds to the extended forecasts. These are all the descendants of the body tag. The example inserts a li tag at the third A short description of the conditions — in this case. a and p are extremely common html tags. In the examples, we will use the following HTML file: In the first example, we use BeautifulSoup module to get three tags. We’ll now add our first content to the page, in the form of the p tag. The example retrieves all descendants of the body tag. If you click around on the console, and explore the div, you’ll discover that each forecast item (like “Tonight”, “Thursday”, and “Thursday Night”) is contained in a div with the class tombstone-container. In HTML, tags are nested, and can go inside other tags. Web scraping is a technique that lets us use programming to do the heavy lifting. It contains up-to-date weather forecasts for every location in the US, but that weather data isn’t accessible as a CSV or via API. Note that children returns a list generator, so we need to call the list function on it: The above tells us that there are two tags at the top level of the page — the initial tag, and the tag. The replace_with replaces a text of an element. A good next step would be to pick a site and try some web scraping on your own. The find_all method can take a list of elements We can add classes and ids to our example: As you can see, adding classes and ids doesn’t change how the tags are rendered at all. As we mentioned at the beginning of the article, it’s important to determine a website’s policy on web scraping before you attempt scraping it. Python BeautifulSoup tutorial is an introductory tutorial to BeautifulSoup Python library. of its parent. But many websites with useful data don’t offer these convenient options. With the right code, pretty much any data that’s on a public-facing website can be downloaded, filtered, and formatted with web scraping. We’ll extract data about the extended forecast. When we visit a web page, our web browser makes a request to a web server. For example, we can use a regular expression and the Series.str.extract method to pull out the numeric temperature values: We could then find the mean of all the high and low temperatures: We could also only select the rows that happen at night: You should now have a good understanding of how to scrape web pages and extract data. The most important object type, and the one we’ll deal with most often, is the Tag object. The example goes through the document tree and prints the We’ll need to first download it using the requests.get method. by BeautifulSoup. We can also serve HTML pages with a simple built-in HTTP server. As you can see from the image, the page has information about the extended forecast for the next week, including time of day, temperature, and a brief description of the conditions. Whenever it found an H2 tag, it would copy whatever text is inside the tag, and output it in whatever format we specified. Now we get the document from the locally running server. Remember, though, that web scraping consumes server resources for the host website. In the below example, we’ll search for any p tag that has the class outer-text: In the below example, we’ll look for any tag that has the class outer-text: You can also search for items using CSS selectors. Before scraping any website, we should look for a terms and conditions page to see if there are explicit rules about scraping. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. The code example finds ul tag that has mylist id. BeautifulSoup is installed with the above command. prints its parent. Some good examples of data to scrape are: You may also want to keep scraping the National Weather Service, and see what other data you can extract from the page, or about your own city. There’s a lot that happens behind the scenes to render a page nicely, but we don’t need to worry about most of it when we’re web scraping. We use the pip3 command to install the necessary modules. For example, if we wanted to get all of the titles inside H2 tags from a website, we could write some code to do that. We’ll extract weather information about downtown San Francisco from this page. of a tag. BeautifulSoup transforms a complex HTML document into a complex Since the children Cloudy, with a l…, Sunday: Rain likely. to search for. Unfortunately, the vast majority if it isn’t available in conveniently organized CSV files for download and analysis. The example finds a specific element with the find method and These special properties give HTML elements names, and make them easier to interact with when we’re scraping. There are multiple li elements; the line prints the first one. It is also possible to find elements by using regular expressions. There are several different types of requests we can make using requests, of which GET is just one. The example finds all h2 and p elements If you want to capture data from many websites, you’ll need to try web scraping. We’ll write some code that looks at the NWS site, grabs just the data we want to work with, and outputs it in the format we need. One element can have multiple classes, and a class can be shared between elements. 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