diakonos/rss/cleanup.py

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2024-01-17 00:20:44 -05:00
# Copyright 2017-present Michael Hall
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import html.parser
import re
__all__ = ["html_to_text"]
WhitespaceHandler = re.compile("<p>|<br>|<br />|<li>", flags=re.MULTILINE)
# The below is semi-safe for use here,
# wouldn't reccomend copying this without understanding it.
# html cleanup is taken from https://stackoverflow.com/a/7778368
# with some modifications made to better suit the needs of this.
class HTMLTextExtractor(html.parser.HTMLParser): # https://stackoverflow.com/a/7778368
def __init__(self):
super().__init__()
self.result = []
def handle_data(self, d):
self.result.append(d)
def get_text(self):
return "".join(self.result)
def html_to_text(html_data): # https://stackoverflow.com/a/7778368
"""Converts HTML to plain text (stripping tags and converting entities).
>>> html_to_text('<a href="#">Demo<!--...--> <em>(&not; \u0394&#x03b7;&#956;&#x03CE;)</em></a>')
'Demo (\xac \u0394\u03b7\u03bc\u03ce)'
"Plain text" doesn't mean result can safely be used as-is in HTML.
>>> html_to_text('&lt;script&gt;alert("Hello");&lt;/script&gt;')
'<script>alert("Hello");</script>'
Always use html.escape to sanitize text before using in an HTML context!
HTMLParser will do its best to make sense of invalid HTML.
>>> html_to_text('x < y &lt z <!--b')
'x < y < z '
Unrecognized named entities are included as-is. '&apos;' is recognized,
despite being XML only.
>>> html_to_text('&nosuchentity; &apos; ')
"&nosuchentity; ' "
"""
html_data = WhitespaceHandler.sub("\n", html_data)
s = HTMLTextExtractor()
s.feed(html_data)
return s.get_text()