I have worked part time through PT school all but the first month of my first trimester of school. I work as a server anywhere from 20 hours a week to just 8-10 depending on where we were at in the curriculum. Some weeks I could work more than others, so it really just depends! I agree with other posters that some of my classmates didn’t work at all and would say that they couldn’t imagine working... however, I honestly never really had an issue with it unless I overloaded a week that had a lot of exams (my own fault - so sleep was sacrificed in order to study).
All that said, good planning and a flexible job is completely doable in my opinion! But you know you better than anyone else! Whatever you choose, good luck!