这句话里,用except 和 except for 是一个意思。根据:牛津高阶。
except preposition BrE /ɪkˈsept/; NAmE /ɪkˈsept/
(also except for) used before you mention the only thing or person about which a statement is not truesynonym apart fromWe work every day except Sunday.They all came except Matt.I had nothing on except for my socks.