In [1]:
from dsc80_utils import *

Lecture 10 – Web Scraping¶

DSC 80, Summer 2026¶

Agenda 📆¶

  • Review: Accessing HTML.
  • HTML basics.
  • Parsing HTML using BeautifulSoup.
  • Example: Scraping quotes.
  • Example: Scraping the HDSI faculty page.

Review: Accessing HTML¶

Making requests¶

Goal: Access information about HDSI faculty members from the HDSI Faculty page.

Let's start by making a GET request to the HDSI Faculty page and see what the resulting HTML looks like.

In [2]:
import requests
In [3]:
fac_response = requests.get('https://datascience.ucsd.edu/faculty/', verify=False)
fac_response

/Users/msgol/ENTER/envs/dsc80/lib/python3.12/site-packages/urllib3/connectionpool.py:1099: InsecureRequestWarning: Unverified HTTPS request is being made to host 'datascience.ucsd.edu'. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/latest/advanced-usage.html#tls-warnings
  warnings.warn(
Out[3]:
<Response [200]>
In [4]:
fac_text = fac_response.text
len(fac_text)
Out[4]:
323328
In [5]:
print(fac_text[:1000])

<!DOCTYPE html>
<html lang="en-US">
<head>
    <meta charset="UTF-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0" />
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<link rel="profile" href="https://gmpg.org/xfn/11" />
    <title>Faculty &#8211; Halıcıoğlu Data Science Institute &#8211; UC San Diego</title>
                        <script>
                            /* You can add more configuration options to webfontloader by previously defining the WebFontConfig with your options */
                            if ( typeof WebFontConfig === "undefined" ) {
                                WebFontConfig = new Object();
                            }
                            WebFontConfig['google'] = {families: ['Roboto:400,500', 'Jost:400,700']};

                            (function() {
                                var wf = document.createElement( 'script' );
                                wf.src = 'https://ajax.googleapis.com/ajax/libs/webfon

This is not super intuitive to read!

  • It is raw HTML, which web browsers use to display websites.
  • The information we are looking for – faculty information – is in there somewhere, but we have to search for it and extract it, which we wouldn't have to do if we had an API.
  • We'll now look at how HTML documents are structured and how to extract information from them.

APIs vs. scraping¶

  • APIs are made by organizations that host data.
    • For example, X (formally known as Twitter) has an API.
    • APIs provide a code-friendly way to access data.
    • Usually, APIs give us back data as JSON objects.
  • Scraping is the act of emulating a web browser to access its source code.
    • As you'll see in Lab 5, it's not technically supported by most organizations.
    • When scraping, you get back data as HTML and have to parse that HTML to extract the information you want.

The anatomy of HTML documents¶

What is HTML?¶

  • HTML (HyperText Markup Language) is the basic building block of the internet.
  • It defines the content and layout of a webpage, and as such, it is what you get back when you scrape a webpage.
  • See this tutorial for more details.

For instance, here's the content of a very basic webpage.

In [6]:
# Mac or Linux:
# !cat data/example1.html

# Windows:
!type data\example1.html

dataexample1.html not found

Using IPython.display.HTML, we can render it directly in our notebook.

In [7]:
from IPython.display import HTML
HTML(filename=Path('data') / 'example1.html')
Out[7]:
Page title

This is a heading

This is a paragraph.

This is another paragraph.

The anatomy of HTML documents¶

  • HTML document: The totality of markup that makes up a webpage.

  • Document Object Model (DOM): The internal representation of an HTML document as a hierarchical tree structure.

  • HTML element: An object in the DOM, such as a paragraph, header, or title.

  • HTML tags: Markers that denote the start and end of an element, such as <p> and </p>.

No description has been provided for this image
(source)

Useful tags to know¶

Element Description
<html> the document
<head> the header
<body> the body
<div> a logical division of the document
<span> an inline logical division
<p> a paragraph
<a> an anchor (hyperlink)
<h1>, <h2>, ... header(s)
<img> an image

There are many, many more, but these are by far the most common. See this article for examples.

Attributes¶

Tags can have attributes, which further specify how to display information on a webpage.

For instance, <img> tags have src and alt attributes (among others):

<img src="king-selfie.png" alt="A photograph of King Triton." width=500>

Hyperlinks have href attributes:

Click <a href="https://practice.dsc80.com">this link</a> to access past exams.

What do you think this webpage looks like?

In [8]:
# Mac or Linux:
# !cat data/example2.html

# Windows:
!type data\example2.html

dataexample2.html not found

The <div> tag¶

<div style="background-color:lightblue">
  <h3>This is a heading</h3>
  <p>This is a paragraph.</p>
</div>

  • The <div> tag defines a division or a "section" of an HTML document.

    • Think of a <div> as a "cell" in a Jupyter Notebook.

  • The <div> element is often used as a container for other HTML elements to style them with CSS or to perform operations involving them using JavaScript.

  • <div> elements often have attributes, which are important when scraping!

Document trees¶

Under the document object model (DOM), HTML documents are trees. In DOM trees, child nodes are ordered.

No description has been provided for this image

What does the DOM tree look like for this document?

No description has been provided for this image

Parsing HTML using Beautiful Soup¶

Beautiful Soup 🍜¶

  • Beautiful Soup 4 is a Python HTML parser.
    • To "parse" means to "extract meaning from a sequence of symbols".
  • Warning: Beautiful Soup 4 and Beautiful Soup 3 work differently, so make sure you are using and looking at documentation for Beautiful Soup 4.

Example HTML document¶

To start, we'll work with the source code for an HTML page with the DOM tree shown below:

No description has been provided for this image

The string html_string contains an HTML "document".

In [9]:
html_string = '''
<html>
    <body>
      <div id="content">
        <h1>Heading here</h1>
        <p>My First paragraph</p>
        <p>My <em>second</em> paragraph</p>
        <hr>
      </div>
      <div id="nav">
        <ul>
          <li>item 1</li>
          <li>item 2</li>
          <li>item 3</li>
        </ul>
      </div>
    </body>
</html>
'''.strip()
In [10]:
HTML(html_string)
Out[10]:

Heading here

My First paragraph

My second paragraph

  • item 1
  • item 2
  • item 3

BeautifulSoup objects¶

bs4.BeautifulSoup takes in a string or file-like object representing HTML (markup) and returns a parsed document.

In [11]:
import bs4
In [12]:
bs4.BeautifulSoup?

Normally, we pass the result of a GET request to bs4.BeautifulSoup, but here we will pass our hand-crafted html_string.

In [13]:
soup = bs4.BeautifulSoup(html_string)
soup
Out[13]:
<html>
<body>
<div id="content">
<h1>Heading here</h1>
<p>My First paragraph</p>
<p>My <em>second</em> paragraph</p>
<hr/>
</div>
<div id="nav">
<ul>
<li>item 1</li>
<li>item 2</li>
<li>item 3</li>
</ul>
</div>
</body>
</html>
In [14]:
type(soup)
Out[14]:
bs4.BeautifulSoup

BeautifulSoup objects have several useful attributes, e.g. text:

In [15]:
print(soup.text)



Heading here
My First paragraph
My second paragraph




item 1
item 2
item 3

Traversing through descendants¶

The descendants attribute traverses a BeautifulSoup tree using depth-first traversal.

Why depth-first? Elements closer to one another on a page are more likely to be related than elements further away.

No description has been provided for this image
In [16]:
soup.descendants
Out[16]:
<generator object Tag.descendants at 0x1050b0e10>
In [17]:
for child in soup.descendants:
    # print(child) # What would happen if we ran this instead?
    if not isinstance(child, str):
        print(child.name)

html
body
div
h1
p
p
em
hr
div
ul
li
li
li

Finding elements in a tree¶

Practically speaking, you will not use the descendants attribute (or the related children attribute) directly very often. Instead, you will use the following methods:

  • soup.find(tag), which finds the first instance of a tag (the first one on the page, i.e. the first one that DFS sees).
    • More general: soup.find(name=None, attrs={}, recursive=True, text=None, **kwargs).
  • soup.find_all(tag) will find all instances of a tag.

find finds tags!

find returns subtrees¶

Let's try to extract the first <div> subtree.

No description has been provided for this image
In [18]:
soup.find('div')
Out[18]:
<div id="content">
<h1>Heading here</h1>
<p>My First paragraph</p>
<p>My <em>second</em> paragraph</p>
<hr/>
</div>
No description has been provided for this image

Let's try to find the <div> element that has an id attribute equal to 'nav'.

In [19]:
soup.find('div', attrs={'id': 'nav'})
Out[19]:
<div id="nav">
<ul>
<li>item 1</li>
<li>item 2</li>
<li>item 3</li>
</ul>
</div>

find will return the first occurrence of a tag, regardless of its depth in the tree.

In [20]:
# Three li children - we get the first one.
soup.find('li')
Out[20]:
<li>item 1</li>

Using find_all¶

find_all returns a list of all matches.

In [21]:
soup.find_all('div')
Out[21]:
[<div id="content">
 <h1>Heading here</h1>
 <p>My First paragraph</p>
 <p>My <em>second</em> paragraph</p>
 <hr/>
 </div>,
 <div id="nav">
 <ul>
 <li>item 1</li>
 <li>item 2</li>
 <li>item 3</li>
 </ul>
 </div>]
In [22]:
soup.find_all('li')
Out[22]:
[<li>item 1</li>, <li>item 2</li>, <li>item 3</li>]
In [23]:
[x.text for x in soup.find_all('li')]
Out[23]:
['item 1', 'item 2', 'item 3']

Node attributes¶

  • The text attribute of a tag element gets the text between the opening and closing tags.
  • The attrs attribute of a tag element lists all of its attributes.
  • The get method of a tag element gets the value of an attribute.
In [24]:
soup.find('p')
Out[24]:
<p>My First paragraph</p>
In [25]:
soup.find('p').text
Out[25]:
'My First paragraph'
In [26]:
soup.find('div')
Out[26]:
<div id="content">
<h1>Heading here</h1>
<p>My First paragraph</p>
<p>My <em>second</em> paragraph</p>
<hr/>
</div>
In [27]:
soup.find('div').text
Out[27]:
'\nHeading here\nMy First paragraph\nMy second paragraph\n\n'
In [28]:
soup.find('div').attrs
Out[28]:
{'id': 'content'}
In [29]:
soup.find('div').get('id')
Out[29]:
'content'

The get method must be called directly on the node that contains the attribute you're looking for.

In [30]:
soup
Out[30]:
<html>
<body>
<div id="content">
<h1>Heading here</h1>
<p>My First paragraph</p>
<p>My <em>second</em> paragraph</p>
<hr/>
</div>
<div id="nav">
<ul>
<li>item 1</li>
<li>item 2</li>
<li>item 3</li>
</ul>
</div>
</body>
</html>
In [31]:
# While there are multiple 'id' attributes, none of them are in the <html> tag at the top.
soup.get('id')
In [32]:
soup.find('div').get('id')
Out[32]:
'content'

Question 🤔

Consider the following HTML document.

<html>
    <head>
        <title>3*Global-2026-02-04</title>
    </head>
    <body>
        <h1>Spotify Top 3 - Global</h1>
        <table>
            <tr class='heading'>
                <th>Rank</th>
                <th>Artist</th> 
                <th>Song</th>
            </tr>
            <tr class=1>
                <td>1</td>
                <td>Djo</td> 
                <td><a href='https://open.spotify.com/track/3qhlB30KknSejmIvZZLjOD'>End of Beginning</a></td>
            </tr>
            <tr class=2>
                <td>2</td>
                <td>Harry Styles</td> 
                <td><a href='https://open.spotify.com/track/45Z3m6yazmAi4jZuW0tzW0'>Aperture</a></td>
            </tr>
            <tr class=3>
                <td>3</td>
                <td>Taylor Swift</td> 
                <td><a href='https://open.spotify.com/track/53iuhJlwXhSER5J2IYYv1W'>The Fate of Ophelia</a></td>
            </tr>
        </table>
    </body>
</html>

Part 1: How many leaf nodes are there in the DOM tree of this document — that is, how many nodes have no children?

In [33]:
# Create a BeautifulSoup object from the Spotify data.
soup = bs4.BeautifulSoup((Path('data') / 'example3.html').read_text())

Part 2: What does the following line of code evaluate to?

len(soup.find_all("td"))

Part 3: What does the following line of code evaluate to?

soup.find("a").get("href")

Example: Scraping quotes¶

Example: Scraping quotes¶

The website quotes.toscrape.com looks like this:

No description has been provided for this image

Goal: Extract quotes (and relevant metadata) into a DataFrame.

Specifically, let's try to make a DataFrame that looks like the one below:

quote author author_url tags
0 “The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.” Albert Einstein https://quotes.toscrape.com/author/Albert-Einstein change,deep-thoughts,thinking,world
1 “It is our choices, Harry, that show what we truly are, far more than our abilities.” J.K. Rowling https://quotes.toscrape.com/author/J-K-Rowling abilities,choices
2 “There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.” Albert Einstein https://quotes.toscrape.com/author/Albert-Einstein inspirational,life,live,miracle,miracles

The plan¶

Eventually, we will create a single function – make_quote_df – which takes in an integer n and returns a DataFrame with the quotes on the first n pages of quotes.toscrape.com.

To do this, we will define several helper functions:

  • download_page(i), which downloads a single page (page i) and returns a BeautifulSoup object of the response.

  • process_quote(div), which takes in a <div> tree corresponding to a single quote and returns a dictionary containing all of the relevant information for that quote.

  • process_page(divs), which takes in a list of <div> trees corresponding to a single page and returns a DataFrame containing all of the relevant information for all quotes on that page.

Key principle: some of our helper functions will make requests, and others will parse, but none will do both!

  • Easier to debug and catch errors.
  • Avoids unnecessary requests.

Downloading a single page¶

In [34]:
def download_page(i):
    req = requests.get(f"http://quotes.toscrape.com/page/{i}/")
    soup = bs4.BeautifulSoup(req.text)
    return soup

In make_quote_df, we will call download_page repeatedly – once for i=1, once for i=2, ..., i=n. For now, we will work with just page 1.

In [35]:
soup = download_page(1)
soup
Out[35]:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8"/>
<title>Quotes to Scrape</title>
<link href="/static/bootstrap.min.css" rel="stylesheet"/>
<link href="/static/main.css" rel="stylesheet"/>
</head>
<body>
<div class="container">
<div class="row header-box">
<div class="col-md-8">
<h1>
<a href="/" style="text-decoration: none">Quotes to Scrape</a>
</h1>
</div>
<div class="col-md-4">
<p>
<a href="/login">Login</a>
</p>
</div>
</div>
<div class="row">
<div class="col-md-8">
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="change,deep-thoughts,thinking,world" itemprop="keywords"/>
<a class="tag" href="/tag/change/page/1/">change</a>
<a class="tag" href="/tag/deep-thoughts/page/1/">deep-thoughts</a>
<a class="tag" href="/tag/thinking/page/1/">thinking</a>
<a class="tag" href="/tag/world/page/1/">world</a>
</div>
</div>
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“It is our choices, Harry, that show what we truly are, far more than our abilities.”</span>
<span>by <small class="author" itemprop="author">J.K. Rowling</small>
<a href="/author/J-K-Rowling">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="abilities,choices" itemprop="keywords"/>
<a class="tag" href="/tag/abilities/page/1/">abilities</a>
<a class="tag" href="/tag/choices/page/1/">choices</a>
</div>
</div>
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="inspirational,life,live,miracle,miracles" itemprop="keywords"/>
<a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
<a class="tag" href="/tag/life/page/1/">life</a>
<a class="tag" href="/tag/live/page/1/">live</a>
<a class="tag" href="/tag/miracle/page/1/">miracle</a>
<a class="tag" href="/tag/miracles/page/1/">miracles</a>
</div>
</div>
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“The person, be it gentleman or lady, who has not pleasure in a good novel, must be intolerably stupid.”</span>
<span>by <small class="author" itemprop="author">Jane Austen</small>
<a href="/author/Jane-Austen">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="aliteracy,books,classic,humor" itemprop="keywords"/>
<a class="tag" href="/tag/aliteracy/page/1/">aliteracy</a>
<a class="tag" href="/tag/books/page/1/">books</a>
<a class="tag" href="/tag/classic/page/1/">classic</a>
<a class="tag" href="/tag/humor/page/1/">humor</a>
</div>
</div>
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“Imperfection is beauty, madness is genius and it's better to be absolutely ridiculous than absolutely boring.”</span>
<span>by <small class="author" itemprop="author">Marilyn Monroe</small>
<a href="/author/Marilyn-Monroe">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="be-yourself,inspirational" itemprop="keywords"/>
<a class="tag" href="/tag/be-yourself/page/1/">be-yourself</a>
<a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
</div>
</div>
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“Try not to become a man of success. Rather become a man of value.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="adulthood,success,value" itemprop="keywords"/>
<a class="tag" href="/tag/adulthood/page/1/">adulthood</a>
<a class="tag" href="/tag/success/page/1/">success</a>
<a class="tag" href="/tag/value/page/1/">value</a>
</div>
</div>
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“It is better to be hated for what you are than to be loved for what you are not.”</span>
<span>by <small class="author" itemprop="author">André Gide</small>
<a href="/author/Andre-Gide">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="life,love" itemprop="keywords"/>
<a class="tag" href="/tag/life/page/1/">life</a>
<a class="tag" href="/tag/love/page/1/">love</a>
</div>
</div>
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“I have not failed. I've just found 10,000 ways that won't work.”</span>
<span>by <small class="author" itemprop="author">Thomas A. Edison</small>
<a href="/author/Thomas-A-Edison">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="edison,failure,inspirational,paraphrased" itemprop="keywords"/>
<a class="tag" href="/tag/edison/page/1/">edison</a>
<a class="tag" href="/tag/failure/page/1/">failure</a>
<a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
<a class="tag" href="/tag/paraphrased/page/1/">paraphrased</a>
</div>
</div>
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“A woman is like a tea bag; you never know how strong it is until it's in hot water.”</span>
<span>by <small class="author" itemprop="author">Eleanor Roosevelt</small>
<a href="/author/Eleanor-Roosevelt">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="misattributed-eleanor-roosevelt" itemprop="keywords"/>
<a class="tag" href="/tag/misattributed-eleanor-roosevelt/page/1/">misattributed-eleanor-roosevelt</a>
</div>
</div>
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“A day without sunshine is like, you know, night.”</span>
<span>by <small class="author" itemprop="author">Steve Martin</small>
<a href="/author/Steve-Martin">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="humor,obvious,simile" itemprop="keywords"/>
<a class="tag" href="/tag/humor/page/1/">humor</a>
<a class="tag" href="/tag/obvious/page/1/">obvious</a>
<a class="tag" href="/tag/simile/page/1/">simile</a>
</div>
</div>
<nav>
<ul class="pager">
<li class="next">
<a href="/page/2/">Next <span aria-hidden="true">→</span></a>
</li>
</ul>
</nav>
</div>
<div class="col-md-4 tags-box">
<h2>Top Ten tags</h2>
<span class="tag-item">
<a class="tag" href="/tag/love/" style="font-size: 28px">love</a>
</span>
<span class="tag-item">
<a class="tag" href="/tag/inspirational/" style="font-size: 26px">inspirational</a>
</span>
<span class="tag-item">
<a class="tag" href="/tag/life/" style="font-size: 26px">life</a>
</span>
<span class="tag-item">
<a class="tag" href="/tag/humor/" style="font-size: 24px">humor</a>
</span>
<span class="tag-item">
<a class="tag" href="/tag/books/" style="font-size: 22px">books</a>
</span>
<span class="tag-item">
<a class="tag" href="/tag/reading/" style="font-size: 14px">reading</a>
</span>
<span class="tag-item">
<a class="tag" href="/tag/friendship/" style="font-size: 10px">friendship</a>
</span>
<span class="tag-item">
<a class="tag" href="/tag/friends/" style="font-size: 8px">friends</a>
</span>
<span class="tag-item">
<a class="tag" href="/tag/truth/" style="font-size: 8px">truth</a>
</span>
<span class="tag-item">
<a class="tag" href="/tag/simile/" style="font-size: 6px">simile</a>
</span>
</div>
</div>
</div>
<footer class="footer">
<div class="container">
<p class="text-muted">
                Quotes by: <a href="https://www.goodreads.com/quotes">GoodReads.com</a>
</p>
<p class="copyright">
                Made with <span class="zyte">❤</span> by <a class="zyte" href="https://www.zyte.com">Zyte</a>
</p>
</div>
</footer>
</body>
</html>

Parsing a single page¶

Let's look at the page's source code (right click the page and click "Inspect" in Chrome) to find where the quotes in the page are located.

In [36]:
divs = soup.find_all('div',attrs={'class','quote'})
#Now write the equivalent one below with special class_ keyword attribute

divs
Out[36]:
[<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”</span>
 <span>by <small class="author" itemprop="author">Albert Einstein</small>
 <a href="/author/Albert-Einstein">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="change,deep-thoughts,thinking,world" itemprop="keywords"/>
 <a class="tag" href="/tag/change/page/1/">change</a>
 <a class="tag" href="/tag/deep-thoughts/page/1/">deep-thoughts</a>
 <a class="tag" href="/tag/thinking/page/1/">thinking</a>
 <a class="tag" href="/tag/world/page/1/">world</a>
 </div>
 </div>,
 <div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“It is our choices, Harry, that show what we truly are, far more than our abilities.”</span>
 <span>by <small class="author" itemprop="author">J.K. Rowling</small>
 <a href="/author/J-K-Rowling">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="abilities,choices" itemprop="keywords"/>
 <a class="tag" href="/tag/abilities/page/1/">abilities</a>
 <a class="tag" href="/tag/choices/page/1/">choices</a>
 </div>
 </div>,
 <div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“There are only two ways to live your life. One is as though nothing is a miracle. The other is as though everything is a miracle.”</span>
 <span>by <small class="author" itemprop="author">Albert Einstein</small>
 <a href="/author/Albert-Einstein">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="inspirational,life,live,miracle,miracles" itemprop="keywords"/>
 <a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
 <a class="tag" href="/tag/life/page/1/">life</a>
 <a class="tag" href="/tag/live/page/1/">live</a>
 <a class="tag" href="/tag/miracle/page/1/">miracle</a>
 <a class="tag" href="/tag/miracles/page/1/">miracles</a>
 </div>
 </div>,
 <div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“The person, be it gentleman or lady, who has not pleasure in a good novel, must be intolerably stupid.”</span>
 <span>by <small class="author" itemprop="author">Jane Austen</small>
 <a href="/author/Jane-Austen">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="aliteracy,books,classic,humor" itemprop="keywords"/>
 <a class="tag" href="/tag/aliteracy/page/1/">aliteracy</a>
 <a class="tag" href="/tag/books/page/1/">books</a>
 <a class="tag" href="/tag/classic/page/1/">classic</a>
 <a class="tag" href="/tag/humor/page/1/">humor</a>
 </div>
 </div>,
 <div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“Imperfection is beauty, madness is genius and it's better to be absolutely ridiculous than absolutely boring.”</span>
 <span>by <small class="author" itemprop="author">Marilyn Monroe</small>
 <a href="/author/Marilyn-Monroe">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="be-yourself,inspirational" itemprop="keywords"/>
 <a class="tag" href="/tag/be-yourself/page/1/">be-yourself</a>
 <a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
 </div>
 </div>,
 <div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“Try not to become a man of success. Rather become a man of value.”</span>
 <span>by <small class="author" itemprop="author">Albert Einstein</small>
 <a href="/author/Albert-Einstein">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="adulthood,success,value" itemprop="keywords"/>
 <a class="tag" href="/tag/adulthood/page/1/">adulthood</a>
 <a class="tag" href="/tag/success/page/1/">success</a>
 <a class="tag" href="/tag/value/page/1/">value</a>
 </div>
 </div>,
 <div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“It is better to be hated for what you are than to be loved for what you are not.”</span>
 <span>by <small class="author" itemprop="author">André Gide</small>
 <a href="/author/Andre-Gide">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="life,love" itemprop="keywords"/>
 <a class="tag" href="/tag/life/page/1/">life</a>
 <a class="tag" href="/tag/love/page/1/">love</a>
 </div>
 </div>,
 <div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“I have not failed. I've just found 10,000 ways that won't work.”</span>
 <span>by <small class="author" itemprop="author">Thomas A. Edison</small>
 <a href="/author/Thomas-A-Edison">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="edison,failure,inspirational,paraphrased" itemprop="keywords"/>
 <a class="tag" href="/tag/edison/page/1/">edison</a>
 <a class="tag" href="/tag/failure/page/1/">failure</a>
 <a class="tag" href="/tag/inspirational/page/1/">inspirational</a>
 <a class="tag" href="/tag/paraphrased/page/1/">paraphrased</a>
 </div>
 </div>,
 <div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“A woman is like a tea bag; you never know how strong it is until it's in hot water.”</span>
 <span>by <small class="author" itemprop="author">Eleanor Roosevelt</small>
 <a href="/author/Eleanor-Roosevelt">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="misattributed-eleanor-roosevelt" itemprop="keywords"/>
 <a class="tag" href="/tag/misattributed-eleanor-roosevelt/page/1/">misattributed-eleanor-roosevelt</a>
 </div>
 </div>,
 <div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
 <span class="text" itemprop="text">“A day without sunshine is like, you know, night.”</span>
 <span>by <small class="author" itemprop="author">Steve Martin</small>
 <a href="/author/Steve-Martin">(about)</a>
 </span>
 <div class="tags">
             Tags:
             <meta class="keywords" content="humor,obvious,simile" itemprop="keywords"/>
 <a class="tag" href="/tag/humor/page/1/">humor</a>
 <a class="tag" href="/tag/obvious/page/1/">obvious</a>
 <a class="tag" href="/tag/simile/page/1/">simile</a>
 </div>
 </div>]

From each <div>, we can extract the quote, author name, author's URL, and tags.

In [37]:
divs[0]
Out[37]:
<div class="quote" itemscope="" itemtype="http://schema.org/CreativeWork">
<span class="text" itemprop="text">“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”</span>
<span>by <small class="author" itemprop="author">Albert Einstein</small>
<a href="/author/Albert-Einstein">(about)</a>
</span>
<div class="tags">
            Tags:
            <meta class="keywords" content="change,deep-thoughts,thinking,world" itemprop="keywords"/>
<a class="tag" href="/tag/change/page/1/">change</a>
<a class="tag" href="/tag/deep-thoughts/page/1/">deep-thoughts</a>
<a class="tag" href="/tag/thinking/page/1/">thinking</a>
<a class="tag" href="/tag/world/page/1/">world</a>
</div>
</div>
In [38]:
# The quote.
divs[0].find('span', attrs={'class':'text'}).text
Out[38]:
'“The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.”'
In [39]:
# The author.
divs[0].find('small', class_='author').text
Out[39]:
'Albert Einstein'
In [40]:
# The URL for the author.
"quotes.toscrape.com" + divs[0].find('a').get('href')
Out[40]:
'quotes.toscrape.com/author/Albert-Einstein'
In [41]:
# The quote's tags.
divs[0].find('meta').get('content')
Out[41]:
'change,deep-thoughts,thinking,world'

Let's implement our next function, process_quote, which takes in a <div> corresponding to a single quote and returns a dictionary containing the quote's information.

Why use a dictionary? Passing pd.DataFrame a list of dictionaries is an easy way to create a DataFrame.

In [42]:
def process_quote(div):
    quote = div.find('span', class_='text').text
    author = div.find('small', class_='author').text
    author_url = 'https://quotes.toscrape.com' + div.find('a').get('href')
    tags = div.find('meta', class_='keywords').get('content')
    
    return {'quote': quote, 'author': author, 'author_url': author_url, 'tags': tags}
In [43]:
process_quote(divs[-1])
Out[43]:
{'quote': '“A day without sunshine is like, you know, night.”',
 'author': 'Steve Martin',
 'author_url': 'https://quotes.toscrape.com/author/Steve-Martin',
 'tags': 'humor,obvious,simile'}

Our last helper function will take in a list of <div>s, call process_quote on each <div> in the list, and return a DataFrame.

In [44]:
def process_page(divs):
    return pd.DataFrame([process_quote(div) for div in divs])
In [45]:
process_page(divs)
Out[45]:
quote author author_url tags
0 “The world as we have created it is a process ... Albert Einstein https://quotes.toscrape.com/author/Albert-Eins... change,deep-thoughts,thinking,world
1 “It is our choices, Harry, that show what we t... J.K. Rowling https://quotes.toscrape.com/author/J-K-Rowling abilities,choices
2 “There are only two ways to live your life. On... Albert Einstein https://quotes.toscrape.com/author/Albert-Eins... inspirational,life,live,miracle,miracles
... ... ... ... ...
7 “I have not failed. I've just found 10,000 way... Thomas A. Edison https://quotes.toscrape.com/author/Thomas-A-Ed... edison,failure,inspirational,paraphrased
8 “A woman is like a tea bag; you never know how... Eleanor Roosevelt https://quotes.toscrape.com/author/Eleanor-Roo... misattributed-eleanor-roosevelt
9 “A day without sunshine is like, you know, nig... Steve Martin https://quotes.toscrape.com/author/Steve-Martin humor,obvious,simile

10 rows × 4 columns

Putting it all together¶

In [46]:
def make_quote_df(n):
    '''Returns a DataFrame containing the quotes on the first n pages of https://quotes.toscrape.com/.'''
    dfs = []
    for i in range(1, n+1):
        # Download page n and create a BeautifulSoup object.
        soup = download_page(i)
        
        # Create a DataFrame of the information on that page.
        divs = soup.find_all('div', class_='quote')
        df = process_page(divs)
        
        # Append DataFrame to dfs.
        dfs.append(df)
        
    # Stitch all DataFrames together.
    return pd.concat(dfs).reset_index(drop=True)
In [47]:
quotes = make_quote_df(3)
quotes.head()
Out[47]:
quote author author_url tags
0 “The world as we have created it is a process ... Albert Einstein https://quotes.toscrape.com/author/Albert-Eins... change,deep-thoughts,thinking,world
1 “It is our choices, Harry, that show what we t... J.K. Rowling https://quotes.toscrape.com/author/J-K-Rowling abilities,choices
2 “There are only two ways to live your life. On... Albert Einstein https://quotes.toscrape.com/author/Albert-Eins... inspirational,life,live,miracle,miracles
3 “The person, be it gentleman or lady, who has ... Jane Austen https://quotes.toscrape.com/author/Jane-Austen aliteracy,books,classic,humor
4 “Imperfection is beauty, madness is genius and... Marilyn Monroe https://quotes.toscrape.com/author/Marilyn-Monroe be-yourself,inspirational
In [48]:
quotes[quotes['author'] == 'Dr. Seuss']
Out[48]:
quote author author_url tags
14 “I like nonsense, it wakes up the brain cells.... Dr. Seuss https://quotes.toscrape.com/author/Dr-Seuss fantasy
25 “Today you are You, that is truer than true. T... Dr. Seuss https://quotes.toscrape.com/author/Dr-Seuss comedy,life,yourself

The elements in the 'tags' column are all strings, but they look like lists. This is not ideal, as we will see shortly.

Example: Scraping the HDSI faculty page¶

Example: Scraping the HDSI faculty page¶

Let's try to extract a list of HDSI Faculty from datascience.ucsd.edu/faculty.

  • As usual, we start by opening the page, right clicking somewhere on the page, and clicking "Inspect" in Chrome.
  • As we can see, the HTML is much more complicated – this is usually the case for websites in the wild.
In [49]:
fac_response = requests.get('https://datascience.ucsd.edu/faculty/', verify=False)
fac_response

/Users/msgol/ENTER/envs/dsc80/lib/python3.12/site-packages/urllib3/connectionpool.py:1099: InsecureRequestWarning: Unverified HTTPS request is being made to host 'datascience.ucsd.edu'. Adding certificate verification is strongly advised. See: https://urllib3.readthedocs.io/en/latest/advanced-usage.html#tls-warnings
  warnings.warn(
Out[49]:
<Response [200]>
In [50]:
soup = bs4.BeautifulSoup(fac_response.text)

It's not easy identifying which <div>s we want. The Inspect tool makes this easier, but it's good to verify that find_all is finding the right number of elements.

In [51]:
divs = soup.find_all('div', class_='vc_grid-item')
In [52]:
len(divs)
Out[52]:
67

Within here, we need to extract each faculty member's name. It seems like names are stored as text within the <h4> tag.

In [53]:
divs[0]
Out[53]:
<div class="vc_grid-item vc_clearfix col_1-5 vc_grid-item-zone-c-bottom vc_visible-item vc_grid-term-tenure-track vc_grid-term-council vc_grid-term-faculty">
<a aria-label="emily-aiken" class="anchor-link" id="emily-aiken" name="emily-aiken"></a>
<div class="vc_grid-item-mini vc_clearfix"><div class="vc_gitem-animated-block">
<div class="vc_gitem-zone vc_gitem-zone-a vc-gitem-zone-height-mode-auto vc-gitem-zone-height-mode-auto-1-1" style="background-image: url(https://datascience.ucsd.edu/wp-content/uploads/2026/01/headshot-scaled.jpg) !important;"><a aria-label="Emily Aiken" class="vc_gitem-link vc-zone-link" href="https://datascience.ucsd.edu/people/emily-aiken/"></a><img alt="Emily Aiken" class="vc_gitem-zone-img" decoding="async" src="https://datascience.ucsd.edu/wp-content/uploads/2026/01/headshot-scaled.jpg"/>
<div class="vc_gitem-zone-mini"></div>
</div>
</div><div class="vc_gitem-zone vc_gitem-zone-c">
<div class="vc_gitem-zone-mini">
<div class="vc_gitem_row vc_row vc_gitem-row-position-top">
<div class="vc_col-sm-12 vc_gitem-col vc_gitem-col-align-">
<div class="vc_custom_heading vc_gitem-post-data vc_gitem-post-data-source-post_title">
<h4 style="text-align: left"><a href="https://datascience.ucsd.edu/people/emily-aiken/">Emily Aiken</a></h4>
</div>
<div class="vc_gitem-align-left fields">
<div class="field pendari_people_title">Assistant Professor</div>
</div>
<div class="excerpt">
</div>
<div class="terms">
                        Tenure-Track Council Faculty 
                      </div>
</div>
</div>
</div>
</div></div></div>
In [54]:
divs[0].find('h4').text
Out[54]:
'Emily Aiken'

We can also extract job titles:

In [55]:
divs[0].find(class_='pendari_people_title').text
Out[55]:
'Assistant Professor'

Let's create a DataFrame consisting of names and job titles for each faculty member.

In [56]:
names = [div.find('h4').text for div in divs]
names[:10]
Out[56]:
['Emily Aiken',
 'Ilkay Altintas',
 'Tiffany Amariuta',
 'Mikio Aoi',
 'Ery Arias-Castro',
 'Vineet Bafna',
 'Mikhail Belkin',
 'Umesh Bellur',
 'Eddy Keming Chen',
 'Peter Chi']
In [57]:
titles = [div.find(class_='pendari_people_title').text for div in divs]
titles[:10]
Out[57]:
['Assistant Professor',
 'SDSC Chief Data Science Officer & HDSI Founding Faculty Fellow',
 'Assistant Professor',
 'Assistant Professor',
 'Professor',
 'Professor',
 'Professor, HDSI Endowed Chair',
 'Visiting Professor, UCSD HDSI',
 'Associate Professor',
 'Associate Teaching Professor']
In [58]:
faculty = pd.DataFrame({
    'name': names, 
    'title': titles, 
})
faculty.head()
Out[58]:
name title
0 Emily Aiken Assistant Professor
1 Ilkay Altintas SDSC Chief Data Science Officer & HDSI Foundin...
2 Tiffany Amariuta Assistant Professor
3 Mikio Aoi Assistant Professor
4 Ery Arias-Castro Professor

Now we have a DataFrame!

In [59]:
faculty[faculty['title'].str.contains('Teaching') | faculty['title'].str.contains('Lecturer')]
Out[59]:
name title
9 Peter Chi Associate Teaching Professor
15 Justin Eldridge Associate Teaching Professor
30 Marina Langlois Lecturer
... ... ...
41 Giorgio Quer Lecturer
49 Jack Silberman Lecturer
53 Janine Tiefenbruck Lecturer

8 rows × 2 columns

What if we want to get faculty members' pictures?

In [60]:
divs[0]
Out[60]:
<div class="vc_grid-item vc_clearfix col_1-5 vc_grid-item-zone-c-bottom vc_visible-item vc_grid-term-tenure-track vc_grid-term-council vc_grid-term-faculty">
<a aria-label="emily-aiken" class="anchor-link" id="emily-aiken" name="emily-aiken"></a>
<div class="vc_grid-item-mini vc_clearfix"><div class="vc_gitem-animated-block">
<div class="vc_gitem-zone vc_gitem-zone-a vc-gitem-zone-height-mode-auto vc-gitem-zone-height-mode-auto-1-1" style="background-image: url(https://datascience.ucsd.edu/wp-content/uploads/2026/01/headshot-scaled.jpg) !important;"><a aria-label="Emily Aiken" class="vc_gitem-link vc-zone-link" href="https://datascience.ucsd.edu/people/emily-aiken/"></a><img alt="Emily Aiken" class="vc_gitem-zone-img" decoding="async" src="https://datascience.ucsd.edu/wp-content/uploads/2026/01/headshot-scaled.jpg"/>
<div class="vc_gitem-zone-mini"></div>
</div>
</div><div class="vc_gitem-zone vc_gitem-zone-c">
<div class="vc_gitem-zone-mini">
<div class="vc_gitem_row vc_row vc_gitem-row-position-top">
<div class="vc_col-sm-12 vc_gitem-col vc_gitem-col-align-">
<div class="vc_custom_heading vc_gitem-post-data vc_gitem-post-data-source-post_title">
<h4 style="text-align: left"><a href="https://datascience.ucsd.edu/people/emily-aiken/">Emily Aiken</a></h4>
</div>
<div class="vc_gitem-align-left fields">
<div class="field pendari_people_title">Assistant Professor</div>
</div>
<div class="excerpt">
</div>
<div class="terms">
                        Tenure-Track Council Faculty 
                      </div>
</div>
</div>
</div>
</div></div></div>
In [61]:
from IPython.display import Image, display

def show_picture(name):
    idx = faculty[faculty['name'].str.lower().str.contains(name.lower())].index[0]
    display(Image(url=divs[idx].find('img').get('src'), width=200, height=200))
    
show_picture('marina')
No description has been provided for this image

Question 🤔

Recall this HTML document.

<html>
    <head>
        <title>3*Global-2026-02-04</title>
    </head>
    <body>
        <h1>Spotify Top 3 - Global</h1>
        <table>
            <tr class='heading'>
                <th>Rank</th>
                <th>Artist</th> 
                <th>Song</th>
            </tr>
            <tr class=1>
                <td>1</td>
                <td>Djo</td> 
                <td><a href='https://open.spotify.com/track/3qhlB30KknSejmIvZZLjOD'>End of Beginning</a></td>
            </tr>
            <tr class=2>
                <td>2</td>
                <td>Harry Styles</td> 
                <td><a href='https://open.spotify.com/track/45Z3m6yazmAi4jZuW0tzW0'>Aperture</a></td>
            </tr>
            <tr class=3>
                <td>3</td>
                <td>Taylor Swift</td> 
                <td><a href='https://open.spotify.com/track/53iuhJlwXhSER5J2IYYv1W'>The Fate of Ophelia</a></td>
            </tr>
        </table>
    </body>
</html>
In [62]:
# Create a BeautifulSoup object from the Spotify data.
soup = bs4.BeautifulSoup((Path('data') / 'example3.html').read_text())

Part 4: Complete the implementation of the function rank_n, which takes in a positive integer n and returns the name of the n-th ranked song in the HTML document. For instance, rank_n(3) should evaluate to "The Fate of Ophelia".

Note: Your implementation should also work in the case that the page contains more than 3 songs.

def rank_n(n):
    return soup.find("tr", attrs=__(a)__).find_all("td")__(b)__

Summary, next time¶

  • Beautiful Soup is an HTML parser that allows us to (somewhat) easily extract information from HTML documents.
    • soup.find and soup.find_all are the functions you will use most often.
  • When writing code to web scrape:
    • Use "Inspect" to identify the names of tags and attributes that are relevant to the information you want to extract.
    • Separate your logic for making requests and for parsing.

Next time¶

Midterm review in class tomorrow, then we'll move on to regular expressions.