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Stephen Cole
Courses Plus Student 15,809 PointsWhen to use parentheses or not with attributes, methods, and functions.
Something I don't think I understand, fully.
Sometimes, Kenneth uses parentheses after his functions and methods. Sometimes, he doesn't.
I'm not sure what the rule is for this.
Why do I need to use parentheses and when should I not use parenthesis when creating a function/method?
2 Answers
Jeffrey Duarte
9,706 PointsHi Stephen,
Whenever you come across this concern you should ask yourself if you're looking to reference, update or execute the variable.
Attributes will never have parenthesis since they cannot be executed.
Classes have parenthesis because when initially called you're most likely looking to execute the creation of a new object of that class.
Methods will have parenthesis because once created they're meant to be called.
For example:
class Car:
# Attributes
color = 'red'
seats = 4
# Methods
def drive():
return 'Car moved forward 1 mile.'
# Below I create my_car from the Car class.
my_car = Car()
# Below I'm updating the color attribute for my_car.
my_car.color = 'white'
# Below I am referencing the color of my_car.
print('My car is currently {}.'.format(my_car.color))
"""The following would be an execution of a method and would return 'Car moved forward 1 mile.'
Without the parenthesis you would get an error as the method can't simply be referenced but must be called."""
my_car.drive()
I hope this helps.
daniel sousa
7,551 PointsI think the reason that Stephen is confused here is the same reason I was confused - You don't need to call a function if its a property apparently?
Iulia Maria Lungu
16,935 PointsIulia Maria Lungu
16,935 PointsCareful, your last statement is incorrect, Jeffrey Duarte.
my_car.drivewith no calling parenthesis would point to the Car class method definition. It won't throw an error. The output would be something like :<bound method Car.drive of <__main__.Car object at 0x109b61f60>>