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 __init__(self, *args, **kwargs):
        # If True, avoid entering subdirectories, and match everything recursively,
        # unconditionally.
        self.matchrecursive = False
        # If True, avoid entering subdirectories, and return "unsure" for
        # everything. This is set to True when complex re patterns (potentially
        # including "/") are used.
        self.unsurerecursive = False
        # Patterns for matching paths in this directory.
        self._kindpats = []
        # Glob patterns used to match parent directories of another glob
        # pattern.
        self._globdirpats = []
        super(_tree, self).__init__(*args, **kwargs)