def get(self, id, pk='id', deleted=False):
        try:
            if pk == 'id':
                id = int(id)
            if deleted:
                spec = {pk: id}
            else:
                spec = {pk: id, 'data': {'$exists': 1}}
            fields = {'_id': 0}
            row = self.db.docs.find_one(spec, fields)
        except Exception as e:
            raise DatabaseException(e)
        if row:
            return Document(**row)
        raise NotFoundError('%s %s not found' % (pk, id))
def _sparse_rmsprop_update_numpy(self, var, gindexs, gvalues, mg, rms, mom,
                                   lr, decay, momentum, centered):
    mg_t = copy.deepcopy(mg)
    rms_t = copy.deepcopy(rms)
    mom_t = copy.deepcopy(mom)
    var_t = copy.deepcopy(var)
    for i in range(len(gindexs)):
      gindex = gindexs[i]
      gvalue = gvalues[i]
      rms_t[gindex] = rms[gindex] * decay + (1 - decay) * gvalue * gvalue
      denom_t = rms_t[gindex]
      if centered:
        mg_t[gindex] = mg_t[gindex] * decay + (1 - decay) * gvalue
        denom_t -= mg_t[gindex] * mg_t[gindex]
      mom_t[gindex] = momentum * mom[gindex] + lr * gvalue / np.sqrt(denom_t)
      var_t[gindex] = var[gindex] - mom_t[gindex]
    return var_t, mg_t, rms_t, mom_t