(Python Derived Classes) Not getting the correct output

You're invoking the parent init wrongly there...

Here's how you're supposed to do it:

class PersonData:
    def __init__(self):
        self.last_name = ''
        self.age_years = 0

    def set_name(self, user_name):
        self.last_name  = user_name

    def set_age(self, num_years):
        self.age_years = num_years

    # Other parts omitted

    def print_all(self):
        output_str = 'Name: ' + self.last_name + ', Age: ' + str(self.age_years)
        return output_str


class StudentData(PersonData):
    def __init__(self):
        super().__init__()  # Call base class constructor
        self.id_num = 0

    def set_id(self, student_id):
        self.id_num = student_id

    def get_id(self):
        return self.id_num


course_student = StudentData()

course_student = StudentData()
course_student.set_id(9999)
course_student.set_age(20)
course_student.set_name("Smith")

print('%s, ID: %s' % (course_student.print_all(), course_student.get_id()))

I also noticed that in the execution, you were calling course_student.get_id(9999) but I think you meant course_student.set_id(9999)

here's the correct way to pass all test using ZyBooks

class PersonData:
    def __init__(self):
        self.last_name = ''
        self.age_years = 0

    def set_name(self, user_name):
        self.last_name  = user_name

    def set_age(self, num_years):
        self.age_years = num_years

    # Other parts omitted

    def print_all(self):
        output_str = 'Name: ' + self.last_name + ', Age: ' + 
        str(self.age_years)
        return output_str


class StudentData(PersonData):
    def __init__(self):
        PersonData.__init__(self)  # Call base class constructor
        self.id_num = 0

    def set_id(self, student_id):
        self.id_num = student_id
        
    def get_id(self):
        return self.id_num


course_student = StudentData()
course_student.set_name('Smith')
course_student.set_age(20)
course_student.set_id(9999)

print('{}, ID: {}'.format(course_student.print_all(), 
course_student.get_id()))

be sure you dont have the line course_student = StudentData( ) coded twice in your code because then your instructor will know that you copied it and pasted it from another website.