def get_dir_from_zipfile(zip_file, fallback=None):
    """Return the name of the root folder in a zip file.

    :param zip_file: a :class:`zipfile.ZipFile` instance.
    :param fallback: if `None`, the name of the zip file is used. This is
        returned if the zip file contains more than one top-level directory,
        or none at all.
    """
    fallback = fallback or zip_file.filename
    directories = [name for name in zip_file.namelist() if name.endswith("/")
                   and len(PurePath(name).parts) == 1]
    return fallback if len(directories) > 1 else directories[0]
def update_message_data_string(self):
        fuz_start = self.current_label_start
        fuz_end = self.current_label_end
        num_proto_bits = 10
        num_fuz_bits = 16

        proto_start = fuz_start - num_proto_bits
        preambel = "... "
        if proto_start <= 0:
            proto_start = 0
            preambel = ""

        proto_end = fuz_end + num_proto_bits
        postambel = " ..."
        if proto_end >= len(self.message_data) - 1:
            proto_end = len(self.message_data) - 1
            postambel = ""

        fuzamble = ""
        if fuz_end - fuz_start > num_fuz_bits:
            fuz_end = fuz_start + num_fuz_bits
            fuzamble = "..."

        self.ui.lPreBits.setText(preambel + self.message_data[proto_start:self.current_label_start])
        self.ui.lFuzzedBits.setText(self.message_data[fuz_start:fuz_end] + fuzamble)
        self.ui.lPostBits.setText(self.message_data[self.current_label_end:proto_end] + postambel)
        self.set_add_spinboxes_maximum_on_label_change()