How to Isolate Class Data for Individual Instances

To avoid having class data shared among multiple instances and ensure each instance maintains its own data, follow these steps:

Declare Variables within the Constructor (__init__ Method)

Instead of declaring class-level variables outside of any method, define them within the init constructor method. For example:

class a:
    def __init__(self):
        self.list = []  # Declared within __init__ to create instance-specific lists

By initializing the list within __init__, a new instance of the list is created alongside each new instance of the object.

Sample Code:

class a:
    def __init__(self):
        self.list = []

x = a()
y = a()

x.list.append(1)
y.list.append(2)
x.list.append(3)
y.list.append(4)

print(x.list)  # prints [1, 3]
print(y.list)  # prints [2, 4]

In this example, the list is no longer shared between the two instances (x and y), and each instance maintains its own separate data, as desired.