in someone's good books

US /ɪn ˈsʌm.wʌnz ɡʊd bʊks/
UK /ɪn ˈsʌm.wʌnz ɡʊd bʊks/
"in someone's good books" picture
1.

to be in favor with someone because you have pleased them

:
I'm trying to get in my boss's good books by finishing this project early.
She's always in her teacher's good books because she's a diligent student.