How to define different addresses for class attributes and instance attributes?

Question

This problem has bothered me for a long time, unless I delete the definition of the class attribute, but want to use the class attribute.

I have defined a dict with the same name in the class attribute and instance attribute. How can I make the memory address different? I tried a variety of methods to delete the content of the class attribute. Is there any other method?

My demo code is as follows:

class MyClass:
    bar: dict = {}

    def __init__(self):
        bar: dict = {}


print(id(MyClass.bar))
a = MyClass()
print(id(a.bar))

1914627629760
1914627629760

score 1 · Accepted Answer · answered Oct 25 '21 at 20:28

class MyClass:
    bar: dict = {}

    def __init__(self):
        self.bar = {}


print(id(MyClass.bar))
a = MyClass()
print(id(a.bar))

2318292079808
2318295104384

That said, I have no idea why we are doing this, and there is an almost 100% chance this will make whomever (next) maintains this codebase go insane within the next 2 years.

Explanation:

You are not "saving" your variable in your __init__() function.

Try running:

class MyClass:
    def __init__(self):
        self.a = 1 # setting attribute a to value 1
        b = 2 # b is not an attribute, it's just a local variable

m = MyClass()
print(m.a) # this will work
print(m.b) # this will not

How to define different addresses for class attributes and instance attributes?

1 Answers1