If the string you are searching for will be in the HTML literally, then simple string replacement will be fine:
old_html = open(html_file).read()
new_html = old_html.replace(my_string, "")
if new_html != old_html:
open(html_file, "w").write(new_html)
As an example of the string not being in the HTML literally, suppose you are looking for "Test" as you said. Do you want it to match these snippets of HTML?:
<a href='test.html'>Test</a>
<A HREF='test.html'>Test</A>
<a href="test.html" class="external">Test</a>
<a href="test.html">Test</a>
and so on: the "same" HTML can be expressed in many different ways. If you know the precise characters used in the HTML, then simple string replacement is fine. If you need to match at an HTML semantic level, then you'll need to use more advanced tools like BeautifulSoup, but then you'll also have potentially very different HTML output than you started with, even in the sections not affected by the deletion, because the entire file will have been parsed and reconstituted.
To execute code over many files, you'll find os.path.walk
useful for finding files in a tree, or glob.glob
for matching filenames to shell-like wildcard patterns.