Classes and Objects in Python — Python Technical Interview Questions & Answers

Classes and Objects in Python

Classes and Objects in Python

  • A class is the blueprint. An object is one real thing made from it. class Student: is the idea of a student. s = Student("Asha", 12) is one student sitting in the room. Two objects can have different names and rolls.
  • __init__ runs when you create the object. self is that object. self.name = name stores the field on it. Forget self and you get TypeError or a variable that vanishes. Every method’s first parameter is self — you don’t pass it at the call site.
  • Let’s take this on the board. class Student with __init__(self, name, roll). s = Student("Asha", 12). print(s.roll, s.name) → 12 Asha. Class is Student. Object is s. That is the whole idea for a fresher viva.
  • Classes and Objects in Python — output: 12 Asha. Student is the class; s is one real object.
  class Student   (blueprint)
         │ Student("Asha", 12)
         ▼
   s1 Asha roll 12

Technical Interview Tip: Explain self and __init__ together.

Code Examples for Classes and Objects in Python

Example

# Classes and objects
class Student:
    def __init__(self, name, roll):
        self.name = name
        self.roll = roll

s = Student("Asha", 12)
print(s.roll, s.name)

Classes and Objects in Python — output: 12 Asha. Student is the class; s is one real object.

How to Explain Classes and Objects in Python to an Interviewer

Explain Classes and Objects as if you are teaching a junior — definition, then one tiny script.

Class = blueprint Object = instance

What does the example print, and why?

Classes and Objects in Python — output: 12 Asha

What mistake do freshers make with Classes and Objects?

Self current object