I would like to use the ontology located in file 'om-2.0.rdf' from
https://github.com/HajoRijgersberg/OM/ as it is provided. Unfortunately, the file starts with a useless byte order mark (
https://en.wikipedia.org/wiki/Byte_order_mark#UTF-8), which trips up Owlready2's '_guess_format'. To make Owlready2 more robust (and accept allowed but useless byte order marks in utf-8 files) I suggest to add
if s.startswith(b"\xef\xbb\xbf"): s = s[3:]
after
if isinstance(s, str): s = s.encode("utf-8")
in _guess_format (driver.py)