Add support for Telxius cancelled maintenance notices

[i3dnet-akoopen]

Telxius sends cancelled maintenance notices in a different format (and different email subject)... great 😅

Anyway, this patch should fix that. Passes the tests (new test added as well).

[jvanderaa]

Thanks for this — and for chasing down yet another Telxius format variant. The fixture-plus-both-test-layers approach is exactly right.

One thing I'd like fixed before merge start can be read before it's bound

In parse_list_dates, start is referenced in the elif guard but only assigned inside the if branch. If an EndTime: bullet ever arrives without a preceding Start Time: bullet, that's an UnboundLocalError. It gets wrapped into ParserError upstream, so nothing crashes — but the operator sees a confusing traceback instead of "this schedule list is malformed". The related case worries me a bit more: because start is never reset after a pair is emitted, a Start / End / End sequence silently emits the same start twice rather than failing.

Worth flagging that neither linter catches this — I ran pylint with the repo's rcfile against your version of the file and it scored 10.00/10, so the green CI isn't evidence either way here.

While you're in there: "EndTime" is matched as a literal, missing space and all. That's Telxius's typo, and the day they fix it to End Time the bullet falls through to the legacy branch and dies on text.split(" - ") with ValueError: not enough values to unpack. Normalizing the label makes it survive that. Same for text.split(": "), which depends on the space after the colon.

Something like this covers all of it:

def parse_list_dates(self, items: ResultSet, events: List):
    """Parse list elements to start and end datetime(s)."""
    start = None
    for item in items:
        text = item.get_text(strip=True)
        # Remove optional notes like "(Backup Window)"
        text = text.split("(")[0].strip()
        # Cancellation notices split the window into separate "Start Time:"/"EndTime:" bullets
        label, _, value = text.partition(":")
        label = label.replace(" ", "").lower()
        if label == "starttime":
            start = self.dt2ts(parser.parse(value.strip()))
        elif label == "endtime":
            if start is None:
                raise ValueError(f"Found an end time with no preceding start time: {text}")
            events.append({"start": start, "end": self.dt2ts(parser.parse(value.strip()))})
            start = None
        else:
            start_str, end_str = text.split(" - ")
            events.append({"start": self.dt2ts(parser.parse(start_str)), "end": self.dt2ts(parser.parse(end_str))})

I checked that partition(":") leaves the existing format alone — "12/August/2026 03:30 UTC - ..." produces a label of 12/august/202603, which falls through to else as before. Lowercasing the label also lines up with how parse_bold already matches ("notification number" in bold.text.lower()).

[i3dnet-akoopen]

I've integrated the suggested changes into the parse_list_dates method.