Merge pull request #88 from MIT-Emerging-Talent/specific_calculator

adding my spacific gravity calculator

.vscode/launch.json

@@ -4,6 +4,7 @@
   // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
   "version": "0.2.0",
   "configurations": [
+
     {
       "name": "ET: Debug Python (unittest)",
       "type": "debugpy",

solutions/specific_gravity_calculator.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+A module for calculating the specific gravity of a substance.
+
+Module contents:
+    - calculate_specific_gravity: calculates the specific gravity of a substance given its density.
+
+Created on 06/01/2025
+
+@author: Novel Yonas
+
+Specific Gravity Calculator:
+This module provides functionality to calculate the specific gravity
+of a substance.
+Specific gravity is a dimensionless quantity that compares the density of a substance
+to the density of a reference substance (typically water at 4°C, which has a density
+of 1000 kg/m³).
+
+The specific gravity is calculated using the formula:
+Specific Gravity = Density of substance / Density of reference substance
+
+In this module, we use water at 4°C as the reference substance, with a density of 1000 kg/m³.
+
+Usage:
+    The main function in this module is 'calculate_specific_gravity', which takes
+    the density of a substance as input and returns its specific gravity.
+"""
+
+
+def calculate_specific_gravity(a, w):
+    """
+    Calculates the specific gravity of a rock mass.
+
+    Args:
+      a: Float, weight of the rock mass measured in air.
+      w: Float, weight of the rock mass measured in water.
+
+    Returns:
+      Float: The specific gravity of the rock mass.
+      None: If the weight in air is less than or equal to the weight in water.
+
+    Raises:
+      ValueError: If invalid inputs are provided or the calculation cannot proceed.
+
+    Examples:
+      >>> calculate_specific_gravity(4, 2)
+      2.0
+      >>> calculate_specific_gravity(5, 2)
+      1.6666666666666667
+      >>> calculate_specific_gravity(2, 2)
+
+    """
+    if a <= w:
+        return None  # Return None to indicate an error
+    return a / (a - w)

solutions/tests/test_specific_gravity_calculator.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Unit test class for the `calculate_specific_gravity` function.
+
+This class contains test cases to validate the functionality
+and edge cases of the
+`calculate_specific_gravity` function, ensuring it handles valid inputs, invalid inputs,
+and edge conditions gracefully.
+
+Test cases include:
+- Valid inputs where the specific gravity is correctly calculated.
+- Cases where the weight in air equals or is less than the weight in water.
+- Inputs with negative values to check for proper error handling.
+"""
+
+import unittest
+
+from solutions.specific_gravity_calculator import calculate_specific_gravity
+
+
+class TestCalculateSpecificGravity(unittest.TestCase):
+    """specific_gravity_calculator"""
+
+    def test_valid_input(self):
+        """Test with valid inputs."""
+        self.assertAlmostEqual(calculate_specific_gravity(4, 2), 2.0)
+        self.assertAlmostEqual(calculate_specific_gravity(5, 2), 1.6666666666666667)
+
+    def test_equal_weights(self):
+        """Test when weight in air is equal to weight in water."""
+        self.assertIsNone(calculate_specific_gravity(2, 2))
+
+    def test_weight_in_air_less_than_water(self):
+        """Test when weight in air is less than weight in water."""
+        self.assertIsNone(calculate_specific_gravity(1, 2))
+
+    def test_invalid_inputs(self):
+        """Test with invalid inputs like negative values."""
+        self.assertIsNone(calculate_specific_gravity(-4, 2))
+        self.assertIsNone(calculate_specific_gravity(-4, -2))