@staticmethod?

What is a `@staticmethod`?

It’s a method inside a class
But it doesn’t use self or cls
It means: No need for object or class-level data

Why do we use it?

Sometimes, you just want a utility/helper function related to the class,
But that function doesn’t need to access any property

Example: Bank Account Number Checker

Suppose you're working on a banking app.

You want to make sure that every account number should

Start with 1
Have exactly 10 digits

Now, this rule doesn’t need:

Holder name
Balance
Interest rate

So we don't need self or cls

Just a plain rule

Code:

class BankAccount:
    @staticmethod
    def is_valid_account_number(number):
        return str(number).startswith("1") and len(str(number)) == 10

Use It:

print(BankAccount.is_valid_account_number(1234567890))  # ✅ True
print(BankAccount.is_valid_account_number(9876543210))  # ❌ False

No need to create a BankAccount object
Just use class name to call it

`@staticmethod` — in subclass and object

even if it’s inside a parent class, you can use it like this:

1. Using class name (as usual)

BankAccount.is_valid_account_number("1234567890")  # ✅ works

2. Using subclass name

class SavingsAccount(BankAccount):
    pass

SavingsAccount.is_valid_account_number("1234567890")  # ✅ works

3. Using the object of a subclass

acc = SavingsAccount()
acc.is_valid_account_number("1234567890")  # ✅ works too

yes yes, even from object it works
because the static method is like a normal function, just attached to class
so Python allows calling it from the object, even if it doesn’t use object data

But remember:

It doesn't care which class or object you used to call it
It just runs the same code inside
No self or cls involved

Recap Table

Call From	Works?	Example
Parent class	✅	`BankAccount.is_valid_account_number(...)`
Subclass	✅	`SavingsAccount.is_valid_account_number(...)`
Subclass object	✅	`acc.is_valid_account_number(...)`

Summary:

Feature	Description
Decorator	`@staticmethod`
Access to `self`?	❌ No
Access to `cls`?	❌ No
Use for	Utility/helper method inside the class
Call using	`ClassName.method()`