🚀 Blog 2: Days 8–15 – Python OOP, File Handling & Exception Mastery

After building strong Python basics in the first 7 days, I dove deeper into Object-Oriented Programming (OOP), File Handling, and Error Handling from Day 8 to Day 15 of my #100DaysOfCode journey.

This part of my journey introduced me to writing real-world code structures like classes, reading/writing data to files, and handling errors like a pro.

✅ What I Learned from Day 8 to 15:

🔸 Object-Oriented Programming (OOP) in Python

• Class & Objects – Defined custom blueprints and created objects.

• init() Constructor – Initialized values when creating objects.

• Self Keyword – Referred to current instance of class.

• Instance vs Class Variables – Used self. vs ClassName. to differentiate.

• Methods – Functions defined inside class.

• Inheritance – Reused parent class features in child classes.

• Encapsulation – Controlled access using public, protected _var, private __var.

• Polymorphism – Created methods with same name but different behaviors.

• Abstraction – Used abstract base class and @abstractmethod to enforce method presence.

📌 Mini Project: Bank Account System with deposit, withdraw, and balance using classes.

🔸 File Handling in Python

• Opened files using open()

• Read files: .read(), .readline(), .readlines()

• Wrote content using .write() and .writelines()

• Used with open() for safe handling (auto close)

• Appended data without overwriting

• Managed text files, CSV files (with csv module), Excel files (with openpyxl), and JSON data (with json module)

📌 Practice: Created & read CSV with student data, wrote JSON file from a dictionary

🔸 Exception Handling in Python

• Used try, except blocks to catch errors

• Handled specific errors like ZeroDivisionError, ValueError, FileNotFoundError

• Used finally to always run code (cleanup)

• Raised custom errors using raise

• Defined custom exceptions using class inheritance (e.g. class MyError(Exception))

📌 Mini Program: Built a division calculator with error catching + custom exception if dividing by 0

🙋‍♀️ Let’s Connect!

🔗 Connect with me on LinkedIn
📁 Explore my GitHub Projects

🌟These 8 days were a big step from simple scripts to more real-world and structured programming. I now understand how Python is used in building systems, managing data, and writing clean, safe code.

Sharing to stay consistent and grow publicly — thanks for reading! 💪