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 setRT(self, r, t):
        self.r = r
        self.t = t
        x = self.r * math.cos(self.t)
        y = self.r * math.sin(self.t)
        self.Tail.Eq(self.p1)
        self.Head.setPoint(self.Tail.x + x,self.Tail.y + y)