Inheritance and Polymorphism is a beginner-friendly milestone in Python. Think of it as learning one reliable tool before building a full toolbox.
In simple words, this lesson shows what the concept is, why it matters, and how to use it safely. The goal is clarity: you should be able to explain it to another beginner after reading.
Professional developers still rely on these basics every day. If you master this topic early, writing real-world code becomes much easier.
Detailed explanation of Inheritance and Polymorphism:
1. Start with the smallest working example.
2. Name variables clearly so your future self understands the code.
3. Make one change at a time and rerun the program.
4. Read errors calmly: the message usually points to the exact issue.
5. Prefer simple code over clever code when you are learning.
Beginner mindset:
You are not expected to memorize everything. You are expected to practice, make mistakes, and improve. Write code daily, even if it is only a few lines.
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class Car:
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def __init__(self, brand):
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self.brand = brand
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c = Car('Toyota')
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print(c.brand)
Run this code, change one value, and observe the output.
Example 2
Add class method
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class Counter:
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def __init__(self):
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self.value = 0
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def increment(self):
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self.value += 1
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c = Counter(); c.increment(); print(c.value)
Run this code, change one value, and observe the output.
Example 3
Inheritance basics
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class Animal:
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def speak(self):
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return 'sound'
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class Dog(Animal):
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def speak(self):
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return 'bark'
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print(Dog().speak())
Run this code, change one value, and observe the output.
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class User:
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def __init__(self, name):
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self.name = name
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class Admin(User):
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def __init__(self, name, level):
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super().__init__(name)
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self.level = level
Run this code, change one value, and observe the output.
Example 5
Encapsulation style
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class Bank:
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def __init__(self):
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self._balance = 0
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def deposit(self, amount):
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self._balance += amount
Run this code, change one value, and observe the output.
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class MathTool:
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@staticmethod
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def add(a, b):
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return a + b
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print(MathTool.add(2, 3))
Run this code, change one value, and observe the output.
Example 7
Import a module
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import math
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print(math.sqrt(49))
Run this code, change one value, and observe the output.
Example 8
Create reusable module
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# in helpers.py
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def shout(text):
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return text.upper()
Run this code, change one value, and observe the output.
Example 9
Package structure idea
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# mypackage/
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# __init__.py
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# tools.py
Run this code, change one value, and observe the output.
Example 10
Dataclass example
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from dataclasses import dataclass
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@dataclass
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class Student:
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name: str
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level: int
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print(Student('Ama', 100))
Run this code, change one value, and observe the output.