def METHOD_NAME(self) -> None:
    self.dialect = None
    self.fileobj = open(self.file, encoding="utf-8-sig")
    self.data = self.fileobj.read()
    def sub(s):
        return re.sub(r"^\#.*$", "__comment", s)
    self.data = [
        f"{sub(x)}\n" for x in self.data.split("\n") if sub(x) != "__comment"
    ]
    if self.data:
        if self.data[0].startswith("tags:"):
            tags = str(self.data[0][5:]).strip()
            self.tagsToAdd = tags.split(" ")
            del self.data[0]
        self.updateDelimiter()
    if not self.dialect and not self.delimiter:
        raise Exception("unknownFormat")