class Academy:
    def __init__(self, students):

        self.students = {name: False for name in students}

    def attendance(self, name):
        if name in self.students:
            self.students[name] = True
        else:
            print("등록되지 않은 학생입니다")

academy = Academy(["민수", "지은", "철수"])
academy.attendance("지은")
print(academy.students)