Calculator Project - Demonstration

A simple calculator implementation in Python with three different testing approaches.

Project Structure

.
├── calculator.py                  # Main calculator implementation
├── test_calculator.py            # Basic assertion-based tests
├── test_calculator_unittest.py    # Unittest-based tests
├── test_calculator_pytest.py      # Pytest-based tests
├── requirements.txt              # Project dependencies
└── .github
    └── workflows
        └── test-ci.yml          # GitHub Actions workflow

Setup

Virtual Environment Setup

1. Create a Virtual Environment

   # Windows
   python -m venv venv
   .\venv\Scripts\activate
   
   # macOS/Linux
   python -m venv venv
   source venv/bin/activate

2. Install Dependencies

   pip install -r requirements.txt

3. Install Pytest (if not using requirements.txt)

   pip install pytest pytest-cov

Deactivating Virtual Environment

When you're done working on the project:

deactivate

Usage

Command Line Interface

python calculator.py

from calculator import Calculator

calc = Calculator()

# Basic operations
result1 = calc.add(5, 3)        # Returns 8
result2 = calc.subtract(5, 3)   # Returns 2
result3 = calc.multiply(5, 3)   # Returns 15
result4 = calc.divide(6, 2)     # Returns 3

# Advanced operations
result5 = calc.modulo(7, 3)     # Returns 1
result6 = calc.power(2, 3)      # Returns 8
result7 = calc.square_root(9)   # Returns 3.0

Testing Approaches

1. Basic Assertion Tests (test_calculator.py)

• Uses Python's built-in assert statements
• Simple and straightforward
• Good for learning basics

Run with:

# From project root directory
python test_calculator.py

2. Unittest Framework (test_calculator_unittest.py)

• Uses Python's built-in unittest framework
• Class-based approach
• Detailed test organization

Run with:

# Regular mode
python -m unittest test_calculator_unittest.py

# Verbose mode
python -m unittest test_calculator_unittest.py -v

3. Pytest Framework (test_calculator_pytest.py)

• Modern testing approach
• More features and cleaner syntax
• Supports fixtures and parameterized testing

Run with:

# Run all pytest tests
pytest

# Verbose mode
pytest -v

# With print statements
pytest -v -s

# With coverage reportven  
pytest --cov=calculator

Features

The Calculator class provides:

• Addition (add)
• Subtraction (subtract)
• Multiplication (multiply)
• Division (divide)
• Modulo (modulo)
• Power (power)
• Square Root (square_root)

Test Coverage

All three test suites cover:

• Basic arithmetic operations
• Edge cases:
  • Division by zero
  • Negative numbers
  • Zero values
• Complex operations:
  • Power calculations
  • Square root with precision
  • Modulo operations

Comparison of Testing Approaches

1. Basic Assertions (test_calculator.py)

   • Pros: Simple, easy to understand
   • Cons: Limited features, basic error reporting

2. Unittest (test_calculator_unittest.py)

   • Pros: Built-in, good organization
   • Cons: More verbose, less modern features

3. Pytest (test_calculator_pytest.py)

   • Pros: Modern features, clean syntax, powerful fixtures
   • Cons: Additional dependency, learning curve