**Method Resolution Order** is an order of searching the attributes/methods from Parent classes.

To check this order, you can use the `mro()` built-in method:

class A:
    pass

class B:
    pass

class C(B):
    pass

class D(A):
    pass

class Child(C, D):
    pass

print(Child.mro())

The `mro()` method returns a list of classes that represents the method and attribute search order.

> Note
>
> The `mro()` method can be called via classes, not for instances.

print(int.mro())
print(float.mro())
print(bool.mro())
print(str.mro())

class SomeClass:
    pass

print(SomeClass.mro())

> Note
>
> Pay attention: all objects in Python are inherited from the `object` class.

Let's start! The Object-Oriented Programming basic concepts are waiting for you here! In this section, you will get acquainted with the most important concepts for understanding Object-Oriented Programming.

Inheritance - the first of the OOP principles. The entities can be inherited from other ones. You learn how it works in code here.

Inheritance - the second of the OOP principles. The attributes and methods can be closed inside the class and used by the class only. Here you learn how to code with different access modifiers.

Polymorphism and abstraction are the third and fourth of the OOP principles. These principles are not easy to understand. Here you will get to know them in the simplest ways.

The magic methods make sandbox from Python. It's a unique Python tool you can't see in other languages. Here you learn how to use these methods and about the flexibility that they bring to Python.

In-Depth Python OOP