Why don't we need self reference when we use super().__init__?(such as line 9 down below)
class labourers():
    def __init__(self,name,department,salary):
        self.name = name
        self.department = department
        self.salary = salary
class managers(labourers):
    def __init__(self,name,department,salary,numberofpeople):
        super().__init__(name,department,salary)
        self.numberofpeople = numberofpeople