BMI Calculator

A simple BMI (Body Mass Index) calculator with a graphical user interface.

Project Structure

The project is organized following the separation of concerns principle:

• BMICalculator.py: Contains the user interface logic using Tkinter
• bmi_calculator_core.py: Contains the core BMI calculation logic
• test_bmi_core.py: Contains tests for the core functionality

Screenshot of the Application

Features

• Calculate BMI based on weight (kg) and height (m)
• Display BMI category (Underweight, Normal weight, Overweight, Obesity)
• Color-coded results for better visualization
• Input validation with user-friendly error messages
• Support for both dot and comma as decimal separators

How to Run

1. Make sure you have Python installed

2. Run the application:

   python BMICalculator.py
   

3. To run the tests:

   python test_bmi_core.py
   

Design Decisions

Separation of Concerns

The application follows a clear separation between:

• UI Logic: Responsible for displaying the interface, handling user input, and presenting results
• Business Logic: Responsible for the actual BMI calculations, categorization, and input validation

This separation makes the code:

• More maintainable
• Easier to test
• More reusable (the core logic can be used in other interfaces)

Core Module Functions

The core module provides these main functions:

• calculate_bmi(weight, height): Calculates BMI value
• get_bmi_category(bmi): Determines the health category based on BMI
• get_category_color(category): Returns a color code for the category
• validate_input(weight_str, height_str): Validates user input

Future Improvements

Potential enhancements for the future:

• Add support for imperial units (pounds, inches)
• Save history of calculations
• Provide more detailed health information
• Add data visualization for BMI trends