xml.etree.ElementTree.ParseError: not well-formed

Using Python 3

Error we get:

File "C:/scratch.py", line 27, in run
    tree = ET.fromstring(responses[0].decode(), ET.XMLParser(encoding='utf-8'))
  File "C:\Programs\Python\Python36-32\lib\xml\etree\ElementTree.py", line 1314, in XML
    parser.feed(text)
xml.etree.ElementTree.ParseError: not well-formed (invalid token): line 163, column 1106

Our code:

tree = ET.fromstring(responses[0].decode(), ET.XMLParser(encoding='utf-8'))
    for i in tree.iter('item'):
        try:
            title = i.find('title').text
        except Exception:
            pass

The responses[0] is from a list of url get requests being returned, but in this case of index 0, testing on one specific url: http://feeds.feedburner.com/marginalrevolution/feed

We were able to plug in the XML code to W3 School validator and got:

This page contains the following errors:
error on line 163 at column 31: Input is not in proper UTF-8, indicate encoding! Bytes: 0x0C 0x66 0x69 0x67

But with the ET.XMLParser(encoding='utf-8') property, shouldn't this fix the error when parsing?

The error message W3 Schools validator is misleading. The problem with 0x0c is not that it is invalid UTF-8, it's that it is not a legal character in XML.

0x0c is the form feed control character, so its presence in the document isn't useful. Conforming XML parsers are obliged to reject documents that are not well formed, and you cannot change the rss feed, so the simplest solution is to remove it from the document before processing.

>>> tree = ET.fromstring(original_response, ET.XMLParser(encoding='utf-8'))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.7/xml/etree/ElementTree.py", line 1315, in XML
    parser.feed(text)
xml.etree.ElementTree.ParseError: not well-formed (invalid token): line 185, column 1106

>>> fixed = original_response.replace(b'\x0c', b'')
>>> tree = ET.fromstring(fixed, ET.XMLParser(encoding='utf-8'))
>>> tree
<Element 'rss' at 0x7ff316db6278>