def quote_etag(etag, weak=False):
    """Quote an etag.

    :param etag: the etag to quote.
    :param weak: set to `True` to tag it "weak".
    """
    if '"' in etag:
        raise ValueError('invalid etag')
    etag = '"%s"' % etag
    if weak:
        etag = 'w/' + etag
    return etag
dataset/ETHPy150Open Eforcers/gae-flask-todo/lib/werkzeug/http.py/quote_etag/original