How to reference object methods in a class variable in Python

Question

I have this class which works :

class A:
    def __init__(self):
        self.checks = (self.check1, self.check2)

    def check1(self):
        print("check1")

    def check2(self):
        print("check2")

    def run_all_checks(self):
        for check in self.checks:
            check()

a = A()

a.run_all_checks()

Now I think attribute checks should not belong to every A object, but should be a class attribute, so I'd like to write :

class A:
    checks = (self.check1, self.check2)

    def check1(self):
        print("check1")

    def check2(self):
        print("check2")

    def run_all_checks(self):
        for check in self.checks:
            check()

a = A()

a.run_all_checks()

This version does not work, giving error :

NameError: name 'self' is not defined

Is there a way to achieve that ?

Answer 1

A property probably gets you closest to what you're trying to achieve.

This way, self.checks gives the tuple of the two check functions, but it does so through a getter function that's called on the fly: so there's no extra storage requirement (albeit that storing two references to functions doesn't take much space).

class A:
    @property
    def checks(self):
        return (self.check1, self.check2)

    def check1(self):
        print("check1")

    def check2(self):
        print("check2")

    def run_all_checks(self):
        for check in self.checks:
            check()

a = A()

a.run_all_checks()

which as expected prints

check1
check2