Classes in python - inheritance

class Person:
	def __init__(self, name, age, gender):
		self.__name = name
		self.__age = age
		self.__gender = gender

	def update_age(self):
		self.__age += 1

	def get_name(self):
		return self.__name

	def get_age(self):
		return self.__age

	def get_gender(self):
		return self.__gender

class Student(Person):
	def __init__(self, name, age, gender, school, ct):
		Person.__init__(self, name, age, gender)
		self.__school = school
		self.__class = ct

	def set_class(self, ct):
		self.__class = ct

	def set_school(self, school):
		self.__school = school

	def get_class(self):
		return self.__class

	def get_school(self):
		return self.__school

	def display(self):
		print("Name:", self.get_name()) # Note: inheritance does not imply accessibility
		print("Age:", self.get_age())   # Cannot access directly though it inherits the attributes
		print("Gender:", self.get_gender())
		print("School:", self.get_school())
		print("Class:", self.get_class())

	def __str__(self):
		out = "Name: " + self.get_name() + "\nAge: "+ str(self.get_age()) + "\nGender: " + \
		self.get_gender() + "\nSchool: " + self.get_school() + "\nClass: " + self.get_class()
		return out

def main():
	person = Person("Helen", 22, "F")
	print(person.get_age())
	person.update_age()
	print(person.get_age())

	print()

	student = Student("Helen", 22, "F", "HCI", "17S6A")
	student.display()
	print()
	print(student)

main()