Code Explanation:
1. Global Variable Definition
x = 10
A global variable x is created.
Its value is 10.
This x exists in the module (global) scope.
2. Defining the Metaclass Meta
class Meta(type):
Meta is a metaclass.
Since it inherits from type, it controls how classes are created.
3. Defining __new__ in the Metaclass
def __new__(cls, name, bases, dct):
__new__ in a metaclass runs when a class is being created, not when an object is created.
Parameters:
cls → the metaclass (Meta)
name → name of the class being created ("A")
bases → base classes of A
dct → namespace dictionary of class A
4. Printing dct["x"]
print(dct["x"])
dct contains all attributes defined inside class A.
At this point:
x = 20 has already been executed inside the class body.
So dct["x"] is 20.
This line prints:
20
5. Creating the Class Object
return super().__new__(cls, name, bases, dct)
Calls type.__new__ to actually create the class A.
Without this, class creation would fail.
6. Defining Class A
class A(metaclass=Meta):
Python starts building the class body of A.
All statements inside the class body execute top to bottom.
After execution, the resulting namespace is passed to Meta.__new__.
7. Executing print(x) Inside Class Body
print(x)
Python looks for x:
No x defined yet inside class A
Falls back to global scope
Global x = 10
This line prints:
10
8. Defining Class Attribute x
x = 20
A class attribute x is created for A.
This x is stored in the class namespace (dct).
9. Order of Execution (Very Important)
Actual execution order:
x = 10 (global)
Enter class A
print(x) → prints 10
x = 20 stored in class namespace
Meta.__new__ runs → prints 20
Class A is created
10. Final Output
10
20
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