Code Explanation:
1️⃣ Creating the Class
class A:
This creates a class named A.
The class will define custom behavior for assigning values to its attributes.
2️⃣ Overriding __setattr__()
def __setattr__(self, name, value):
__setattr__() is a special Python method that is automatically called whenever you assign a value to an instance attribute.
For example:
a.x = 5
internally triggers:
a.__setattr__("x", 5)
Here:
name → "x"
value → 5
3️⃣ Modifying the Assigned Value
object.__setattr__(self, name, value * 2)
This is the important line.
Before storing the value, the code multiplies it by 2.
So:
value = 5
value * 2 = 10
Then object.__setattr__() actually stores the value in the object's attributes.
This direct call to object.__setattr__() also avoids recursively calling our overridden __setattr__() again.
4️⃣ Creating an Object
a = A()
An object a is created from class A.
At this point, no custom attribute has been assigned yet.
5️⃣ Assigning x
a.x = 5
This automatically calls:
a.__setattr__("x", 5)
Inside __setattr__():
value * 2
becomes:
5 × 2 = 10
Therefore:
a.x = 10
6️⃣ Assigning y
a.y = 3
Again, __setattr__() is automatically called:
a.__setattr__("y", 3)
The value is doubled:
3 × 2 = 6
Therefore:
a.y = 6
7️⃣ Printing the Values
print(a.x, a.y)
At this point:
a.x = 10
a.y = 6
Therefore Python prints:
10 6
🔄 Execution Flow
a.x = 5
↓
__setattr__("x", 5)
↓
5 × 2
↓
a.x = 10
a.y = 3
↓
__setattr__("y", 3)
↓
3 × 2
↓
a.y = 6
🎯 Final Output
10 6
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