英语帝进 “我从没见过像你这样清纯的女孩”用英语怎么说？

I have never met /seen/ known a girl who is so pure like a lily( 百合） like you .
题主的本意应该是想要赞美这个女孩子，所以在原文的“纯洁”的意思上面补充了一个英文中常见的对女孩的赞美，“像百合花一样的”，百合是非常圣洁高贵又美好纯洁的，女孩子都愿意听到这样的说法。

I have never seen such a pure / an innocent girl as you .
= I never see so pure / innocent a girl as you.
= I have never seen a pure / an innocent girl like you.
关键词语：pure / innocent 清纯的，纯洁的，纯真的； such +a/an + 形容词+名词 = so +形容词+a/an+名词； such...as ...=... like...像......这样的......。例如：
The look from her eye is still so pure, like a dustless crystal. 她的眼神依旧清纯，仿佛水晶般的纤尘不染。
She is a pure young girl. 她是一个纯真无邪的姑娘。
To many, she was like the innocent princess of a thousand fairy tales. 对许多人而言，她就像千篇一律的童话故事里清纯的公主。
I don't like such a person as you. 我不喜欢你这样的人。

No one will like the persons like you.
Everyone will like so clever a boy / such a clever boy as Tom. 每个人都会喜欢像汤姆这样聪明的孩子。

You are such a pure girl I ever seen.( I might've never seen a pure girl f