python

Training a Python to Explore Holes in Dark Patterns

Data Science students are always looking for new and interesting datasets to train machine learning models. There's tons of public data out there. Unfortunately, in the US, many of our "public" datasets are difficult to access. The most interesting data is hidden behind dark patterns on corporate and government websites.

Here you'll see how to use Pandas to easily pull down a lot of data from prosocial websites like wikipedia. Then you'll learn a little BeautifulSoup to scrape out that sneaky data that hides behind dark patterns.

pandas.read_html

If you build web pages with tables in them, they become accessible to anybody who knows how to use Pandas, like this Wikipedia page:

Demographics of the World, wikipedia article with tabular data =1225x386

>>> import pandas as pd
>>> base_url = 'https://en.wikipedia.org'
>>> page_title = 'demographics of the world'
>>> page_url = f'{base_url}/wiki/{page_title.replace(" ", "_")}'
>>> tables = pd.read_html(page_url)
>>> len(tables)
25

Then you can easily find the interesting tables and calculate some statistics:

>>> for df in tables:
...     if len(df) > 10 and len(df.describe().columns) > 1:
...         print('='*70)
...         print(df.describe(include='all'))
...         print('='*70)
...         print()

Here's one of those tables of descriptive statistics:

================================================================================================================================================================
                 Year           0        1000        1500        1600        1700        1820        1870        1913        1950        1973        1998
count              17   17.000000   17.000000   17.000000   17.000000   17.000000   17.000000   17.000000   17.000000   17.000000   17.000000   17.000000
unique             17         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN
top     United States         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN
freq                1         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN         NaN
mean              NaN   17.158824   16.752941   16.829412   16.858824   16.788235   17.064706   17.064706   17.064706   16.911765   16.905882   16.758824
std               NaN   28.360008   26.822684   26.260849   26.968131   26.524938   27.237197   25.845767   24.935666   24.582257   24.890397   25.281887
min               NaN    0.200000    0.200000    0.200000    0.100000    0.100000    0.100000    0.500000    0.800000    0.900000    1.000000    0.900000
25%               NaN    1.300000    2.400000    2.300000    1.100000    1.300000    1.400000    3.100000    4.400000    5.400000    5.400000    4.600000
50%               NaN    2.400000    4.200000    4.000000    3.700000    4.500000    5.300000    7.000000    7.000000    7.100000    7.900000    6.900000
75%               NaN   15.900000   15.400000   20.100000   20.000000   21.000000   20.100000   19.900000   17.000000   15.500000   17.300000   16.500000
max               NaN  100.000000  100.000000  100.000000  100.000000  100.000000  100.000000  100.000000  100.000000  100.000000  100.000000  100.000000
================================================================================================================================================================

Dark Patterns

What's a dark pattern? It's any UX that prevents people from getting things done without manipulation and distraction and lock-in. For a Data Scientist a dark pattern prevents them from accessing data.

When the Internet was new, and only teenagers and geeks knew how to use it, public officials could be forgiven for "publishing" data in PDFs or proprietary spreadsheets and databases. But we live in an era where elected officials responsible for securing voter registration data have the skill to deploy dark pattern websites that support their political agenda. And the skill to do this sort of sophisticated technical work is not limited to advanced, stable democracies like the United States. Officials in charge of data in most developing countries are also deploying sophisticated web applications that breach the public trust. Do a Duck search for "Brian Kemp suppression" if you want to learn more. He was so adept at managing his IT department, he successfully made voter registration data accessible only to his supporters and campaign managers. And using predictive analytics on this data, he was able to delete the voter registrations for those that would likely vote against him in his campaign for Governor.

Illuminating the Dark

So I'll show you how easy it is to process data from prosocial public data sources like Wikipedia. And then I'll show you the problem with some dark patterns on the web. Some are intentional and some are not, but we'll help you illuminate the data you want and scrape it.

There are no options for the pd.read_html function that do what you want. So when I tried to get a list of business names from the California Department of State website, I get everything except the name when Pandas automatically parses the HTML:

>>> import pandas as pd
>>> bizname = 'poss'
>>> url = f'https://businesssearch.sos.ca.gov/CBS/SearchResults?filing=&SearchType=CORP&SearchCriteria={bizname}&SearchSubType=Begins'
>>> df = pd.read_html(url)[0]
>>> df

    Entity Number Registration Date         Status                                        Entity Name Jurisdiction      Agent for Service of Process
0      C2645412        04 / 02 / 2004         ACTIVE  View details for entity number 02645412  POSSU...      GEORGIA   ERESIDENTAGENT, INC. (C2702827)
1      C0786330        09 / 22 / 1976      DISSOLVED  View details for entity number 00786330  POSSU...   CALIFORNIA                        I. HALPERN
2      C2334141        03 / 01 / 2001  FTB SUSPENDED  View details for entity number 02334141  POSSU...   CALIFORNIA                   CLAIR G BURRILL
3      C0658630        11 / 08 / 1972  FTB SUSPENDED  View details for entity number 00658630  POSSU...   CALIFORNIA                               NaN
4      C1713121        09 / 23 / 1992  FTB SUSPENDED  View details for entity number 01713121  POSSU...   CALIFORNIA                LAWRENCE J. TURNER
5      C1207820        08 / 05 / 1983      DISSOLVED  View details for entity number 01207820  POSSU...   CALIFORNIA                          R L CARL
6      C3921531        06 / 27 / 2016         ACTIVE  View details for entity number 03921531  POSSU...   CALIFORNIA  REGISTERED AGENTS INC(C3365816)

The website hides business names behind a button. But you can use requests to download the raw html. Then you can use bs4 to extract the raw HTML table as well as any particular row(< tr >) or cell(< td >) that you want.

First lets see how public APIs and the semantic web are supposed to work. Say I read a great SciFi novel, Three Body Problem and wanted to find other books that, like it, won the Hugo Award for best novel. This is how you search for something on wikipedia:

>>> import requests
>>> base_url = 'https://en.wikipedia.org'
>>> search_text = 'hugo award best novel liu'
>>> search_results = requests.get(
...     'https://en.wikipedia.org/w/index.php',
...     {'search': search_text},
... )
>>> search_results

<Response [200]>

Now we can programmatically find the page with the Hugo Awards using BeautifulSoup4. Don't try to install BeautifulSoup without tacking on that version 4 to the end. Otherwise you'll get some confusing error messages. And the import name is bs4, not beautifulsoup. The .find() method finds the first element in a BeautifulSoup object. So if you want to walk through the list of search result, use .findall().

You only need the first search result for this carefully crafted search; ):

>>> import bs4
>>> soup = bs4.BeautifulSoup(search_results.text)
>>> soup.find('div', {'class': 'searchresults'})
>>> soup = (soup.find('div', {'class': 'searchresults'}) or soup).find('ul')
>>> hugo_url = (soup.find('li') or soup).find('a', href = True).get('href')
>>> hugo_url

'/wiki/Hugo_Award_for_Best_Novel'

So now we can join the wikipedia path with the base_url to get to the page containing the data table we're looking for. And we can use Pandas to deal download and parse it directly, without any fancy BeaufulSouping.

Some of this code is on stack overflow in the answer to["Pandas read_html to return raw HTML"](https: // stackoverflow.com / a / 65755142 / 623735).

>>> soup = bs4.BeautifulSoup(requests.get(url).text)
>>> table = soup.find('table').findAll('tr')
>>> names = []
... for row in table:
...     names.append(getattr(row.find('button'), 'contents', [''])[0].strip())
>>> names[-7:]

['POSSUM FILMS, INC',
 'POSSUM INC.',
 'POSSUM MEDIA, INC.',
 'POSSUM POINT PRODUCTIONS, INC.',
 'POSSUM PRODUCTIONS, INC.',
 'POSSUM-BILITY EXPRESS, INCORPORATED',
 'POSSUMS WELCOME']

Now you can replace that useless column with the correct Button Text, the names of the businesses we're interested in. You need to ignore the first row in the HTML table, because it contains the header "Entity Name" and does not have a button tag:

>>> df['Entity Name'] = names[1:]
>>> df.tail()

    Entity Number Registration Date         Status                  Entity Name Jurisdiction Agent for Service of Process
96       C2334141        03/01/2001  FTB SUSPENDED           POSSUM MEDIA, INC.   CALIFORNIA              CLAIR G BURRILL
97       C0658630        11/08/1972  FTB SUSPENDED  POSSUM POINT PRODUCTIONS...   CALIFORNIA                          NaN
98       C1713121        09/23/1992  FTB SUSPENDED     POSSUM PRODUCTIONS, INC.   CALIFORNIA           LAWRENCE J. TURNER
99       C1207820        08/05/1983      DISSOLVED  POSSUM-BILITY EXPRESS, I...   CALIFORNIA                     R L CARL
100      C3921531        06/27/2016         ACTIVE              POSSUMS WELCOME   CALIFORNIA  REGISTERED AGENTS INC (C...

Resources

If you're working on an NLP problem, you can get data from Wikipedia the propper way... with a database dump: TDS Post on working with Wikipedia data dumps

Hacker Public Radio is awesome! I'm going to try to record my first podcast today, based on this blog post. I'll share these ideas for scraping public data out through the holes in dark patterns with Python (Pandas, Beautiful Soup). It'll be good practice for the monthly meetup
San Diego Python User Group.

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