'Remove tag from cache
Args:
key (str): A cleaned key string
category (str or None): A cleaned category name'

def _delcache(self, key, category):

    (key, category) = (key.strip().lower(), (category.strip().lower() if category else category))
    catkey = ('-%s' % category)
    if key:
        cachekey = ('%s-%s' % (key, category))
        self._cache.pop(cachekey, None)
    else:
        [self._cache.pop(key, None) for key in self._cache if key.endswith(catkey)]
    self._catcache.pop(catkey, None)
    self._cache_complete = False
