Highlight clippings on an ebook

highlight-ebook-clippings.py

#!/usr/bin/env python3

# Highlight clippings on an ebook
# Input:
# - clippings file (generated by Calibre -- 
#   see https://www.mobileread.com/forums/showthread.php?t=76069)
# - ebook in HTML format (exported by Calibre)
#
# Output:
# - HTML ebook with highlights in yellow
#

import re

BOOK_PATH = 'book/index.html'
CLIPPINGS_PATH = 'clippings.txt'
OUTPUT_PATH = 'book-annotated.html'

# Read book
with open(BOOK_PATH) as f:
    html = f.read()
    html = re.sub('<a id="calibre_link-.+?"></a>', '', html)

# Read clippings
with open(CLIPPINGS_PATH) as f:
    clippings = f.read()
    items = clippings.split('==========\n')
    highlights = []
    for item in items:
        highlights.append(item.split('\n')[3])

# Highlight
for highlight in highlights:
    html = html.replace(highlight, f'<span style="background: yellow;">{highlight}</span>')

# Output
with open(OUTPUT_PATH, 'w') as f:
    f.write(html)