🧮 Introduction: Building a Real Calculator in Python
After working through focused exercises like fruit calculators and sorters, it’s time to bring everything together into something familiar and practical — a calculator.
This notebook implements a basic calculator using Python, covering arithmetic operations, function abstraction, and operator-based decision logic. It’s simple, readable, and intentionally beginner-friendly.
🎯 Purpose: Practicing Core Programming Skills
The purpose of this notebook is to reinforce several foundational concepts at once:
- Writing reusable functions
- Performing common arithmetic operations
- Using conditionals to route logic
- Handling basic runtime errors (like division by zero)
Together, these form the backbone of many real-world programs.
🧠 How It Works: High-Level Flow
The calculator follows a clear, structured flow:
- Define individual functions for arithmetic operations
- Create a wrapper function to act as the calculator engine
- Pass operands and an operator into the calculator
- Execute the correct operation and return the result
This separation of responsibilities keeps the code easy to read and extend.
🧩 The Technical Part: Functions and Operators
A simplified version of the logic looks like this:
def add(x, y):
return x + y
def subtract(x, y):
return x - y
def multiply(x, y):
return x * y
def divide(x, y):
if y == 0:
return "Error: Division by zero"
return x / y
def calculator(x, y, operator):
if operator == "+":
return add(x, y)
elif operator == "-":
return subtract(x, y)
elif operator == "*":
return multiply(x, y)
elif operator == "/":
return divide(x, y)
else:
return "Invalid operator"
🔍 What This Demonstrates
- 🧩 Each operation is encapsulated in its own function
- 🔀 Conditional logic routes execution based on the operator
- 🛡 Basic error handling prevents crashes
- 🧠 The calculator logic stays clean and readable
This is an early example of command routing, a pattern used in APIs and applications.
💡 Key Takeaways: From Syntax to Structure
From this notebook, we learn that:
- 🧱 Functions improve clarity and reuse
- 🔁 Control flow determines program behaviour
- ⚠️ Guarding against invalid input is essential
- 🛠 Clean structure matters more than clever code
These ideas scale directly into larger systems.
🏁 Conclusion: A Foundational Building Block
The Calculator notebook represents a key milestone:
You’re no longer experimenting with isolated statements — you’re composing logic into a working program.
With this foundation, you’re well prepared to explore:
- Loops for continuous input
- Dictionaries for operator mapping
- User-driven calculator menus
- Object-oriented calculator designs
Every complex system starts with a simple calculator.
🔗 Link to Notebook
Notebook link: Coming Soon