在Python中使用变量修改参数名称

I'm translating PHP code to Python code which inserts data into a MySql table.

There are four possible columns based on a naming convention: image_ + [hq,sq, lq, thumb] + _url

The php code is as follows (using Laravel DB Query):

DB::table('items')
                ->insertGetId(array(
                   'title' => $title,
                    'image_' . $quality . '_url' => $amazon_url,
                ));

The corresponding python code (using SqlAlchemy Core) which is giving me a syntax error:

item_ins = items_tbl.insert().values(title=item_title, 
                                                   image_+quality+_url=amazon_url

            )

How can I accomplish the same result in Python without reverting to if/else statements?