Software development and beyond

How to extract plain text from an HTML page in Python

There are many different ways to extract plain text from HTML and some are better than others depending on what we want to extract and if we know where to find it. In this article I will demonstrate a simple way to grab all text content from the HTML source so that we end up with a concatenated string of all texts on the page.

We will do it with Python and Beautiful Soup 4, a Python library for scraping information from web pages. So to start off, let’s install beautifulsoup4 package and lxml parser (this is a fast parser that can be used together with BS):

# install using pip
pip install --user beautifulsoup4
pip install --user lxml

# install using poetry
poetry add beautifulsoup4
poetry add lxml

Now we will import Beautiful Soup’s classes for working with HTML: BeautifulSoup for parsing the source and Tag which we are going to use for checking whether a particular element in the parsed BeautifulSoup tree represents an HTML tag.

Besides the necessary imports, we will also define a list of block elements that we want to extract the text from. I have picked p for paragraphs, h1-h5 for headings and blockquote for quotes as an example:

from bs4 import BeautifulSoup
from bs4.element import Tag

blocks = ["p", "h1", "h2", "h3", "h4", "h5", "blockquote"]

Our main function to_plaintext(html_text: str) -> str will take a string with the HTML source and return a concatenated string of all texts from our selected blocks:

def to_plaintext(html_text: str) -> str:
soup = BeautifulSoup(html_text, features="lxml")
extracted_blocks = _extract_blocks(soup.body)
extracted_blocks_texts = [block.get_text().strip() for block in extracted_blocks]
return "\n".join(extracted_blocks_texts)

The last thing is to define _extract_blocks() function that will take a root element and return all block elements that we are interested in:

def _extract_blocks(parent_tag) -> list:
extracted_blocks = []
for tag in parent_tag:
if in blocks:
if isinstance(tag, Tag):
if len(tag.contents) > 0:
inner_blocks = _extract_blocks(tag)
if len(inner_blocks) > 0:
return extracted_blocks

And that’s all!

Last updated on 16.10.2020.

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