Feat: add solution for 15 challenge, convert binary to a decimal number

add tests aswell

solutions/__init__.py

@@ -1 +0,0 @@
-

solutions/challenge_15/README.MD

@@ -0,0 +1,32 @@
+# Challenge: Convert Binary Numbers to Decimal
+
+## Description
+
+The "Binary to Decimal" challenge involves converting a binary number (base 2)
+into its decimal (base 10) equivalent.
+
+Binary numbers consist of only two digits: 0 and 1,
+where each digit represents a power of 2.
+
+Write a function that takes a binary number as a string
+and returns its decimal equivalent as an integer.
+
+For example:
+
+- The binary number `1010` equals `10` in decimal.
+- The binary number `1111` equals `15` in decimal.
+
+## Example
+
+```python
+binary_to_decimal('1010')
+# Output: 10 (binary 1010 = decimal 10)
+
+binary_to_decimal('1111')
+# Output: 15 (binary 1111 = decimal 15)
+
+binary_to_decimal('1001')
+# Output: 9 (binary 1001 = decimal 9)
+```
+
+[Github issue](https://github.com/MIT-Emerging-Talent/ET6-foundations-group-04/issues/15)

solutions/challenge_15/__init__.py

@@ -0,0 +1 @@
+

solutions/challenge_15/solution.py

@@ -0,0 +1,38 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+A module for converting binary numbers to decimal equivalents.
+
+Module contents:
+    - binary_to_decimal: Converts a binary string to its decimal equivalent
+
+Created on 28/12/2024
+Author: Ramon Colmenares
+"""
+
+
+def binary_to_decimal(binary_str: str) -> int:
+    """Converts a binary string to its decimal equivalent.
+
+    Parameters:
+        binary_str: str, a binary number as a string
+
+    Returns -> int: the decimal equivalent of the binary number
+
+    Raises:
+        ValueError: if the input is not a valid binary string
+
+    Examples:
+        >>> binary_to_decimal('1010')
+        10
+        >>> binary_to_decimal('1111')
+        15
+        >>> binary_to_decimal('1001')
+        9
+    """
+    decimal_value = 0
+    for i, digit in enumerate(reversed(binary_str)):
+        if digit not in {"0", "1"}:
+            raise ValueError(f"Invalid binary digit '{digit}' in input")
+        decimal_value += int(digit) * (2**i)
+    return decimal_value

solutions/tests/challenge_15/test_binary_to_decimal.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Test module for binary_to_decimal function.
+
+Test categories:
+    - Standard cases: typical binary strings
+    - Edge cases: single-bit binary strings, leading zeros
+    - Defensive tests: invalid inputs, non-binary strings
+
+Created on 2024-12-06
+Author: Your Name
+"""
+
+import unittest
+
+from solutions.challenge_15.solution import binary_to_decimal
+
+
+class TestBinaryToDecimal(unittest.TestCase):
+    """Test suite for the binary_to_decimal function."""
+
+    def test_simple_binary(self):
+        """
+        It should return the correct decimal
+        value for typical binary strings
+        """
+        self.assertEqual(binary_to_decimal("1010"), 10)
+        self.assertEqual(binary_to_decimal("1111"), 15)
+        self.assertEqual(binary_to_decimal("1001"), 9)
+
+    def test_single_bit_binary(self):
+        """
+        It should return the correct decimal
+        value for single-bit binary strings
+        """
+        self.assertEqual(binary_to_decimal("0"), 0)
+        self.assertEqual(binary_to_decimal("1"), 1)
+
+    def test_leading_zeros(self):
+        """It should correctly handle binary strings with leading zeros"""
+        self.assertEqual(binary_to_decimal("0000"), 0)
+        self.assertEqual(binary_to_decimal("0001"), 1)
+        self.assertEqual(binary_to_decimal("001010"), 10)
+
+    def test_invalid_binary_string(self):
+        """It should raise a ValueError for invalid binary strings"""
+        with self.assertRaises(ValueError):
+            binary_to_decimal("2")
+        with self.assertRaises(ValueError):
+            binary_to_decimal("abc")
+        with self.assertRaises(ValueError):
+            binary_to_decimal("10.01")