From 7aaff2261c99eaa0ae731e1193a0c972b8c77a8a Mon Sep 17 00:00:00 2001
From: NikolaPavlov <nikola.pavlov1955@gmail.com>
Date: Sun, 19 Apr 2015 21:30:57 +0300
Subject: [PATCH]  add week2 Fraction

---
 week2/4-Fractions/p04_anImmutableFraction.py  | 63 +++++++++++++++
 .../p04_test_anImmutableFraction.py           | 78 +++++++++++++++++++
 2 files changed, 141 insertions(+)
 create mode 100644 week2/4-Fractions/p04_anImmutableFraction.py
 create mode 100644 week2/4-Fractions/p04_test_anImmutableFraction.py

diff --git a/week2/4-Fractions/p04_anImmutableFraction.py b/week2/4-Fractions/p04_anImmutableFraction.py
new file mode 100644
index 0000000..8f0a27e
--- /dev/null
+++ b/week2/4-Fractions/p04_anImmutableFraction.py
@@ -0,0 +1,63 @@
+class Fraction:
+
+    def __init__(self, nominator, denominator):
+        self.nomi = nominator
+        self.denomi = denominator
+
+    def __str__(self):
+        if self.nomi % self.denomi == 0:
+            return str(int(self.nomi / self.denomi))
+        else:
+            return "{} / {}".format(self.nomi, self.denomi)
+
+    def __repr__(self):
+        return self.__str__()
+
+    def __eq__(self, other):
+        if self.nomi / self.denomi == other.nomi / other.denomi:
+            return True
+        return False
+
+    @staticmethod
+    def reduce_fraction(fraction):
+        for i in range(fraction.nomi, 0, -1):
+            if fraction.nomi % i == 0 and fraction.denomi % i == 0:
+                fraction.nomi /= i
+                fraction.denomi /= i
+        return Fraction(int(fraction.nomi), int(fraction.denomi))
+
+    def __add__(self, other):
+        if isinstance(self, int):
+            self = Fraction(self, 1)
+
+        if isinstance(other, int):
+            other = Fraction(other, 1)
+
+        new_nominator = self.nomi * other.denomi + self.denomi * other.nomi
+        new_denominator = self.denomi * other.denomi
+        new_fraction = Fraction(new_nominator, new_denominator)
+        return Fraction.reduce_fraction(new_fraction)
+
+    def __sub__(self, other):
+        if isinstance(self, int):
+            self = Fraction(self, 1)
+
+        if isinstance(other, int):
+            other = Fraction(other, 1)
+
+        new_nominator = self.nomi * other.denomi - self.denomi * other.nomi
+        new_denominator = self.denomi * other.denomi
+        new_fraction = Fraction(new_nominator, new_denominator)
+        return Fraction.reduce_fraction(new_fraction)
+
+    def __mul__(self, other):
+        if isinstance(self, int):
+            self = Fraction(self, 1)
+
+        if isinstance(other, int):
+            other = Fraction(other, 1)
+
+        new_nominator = self.nomi * other.nomi
+        new_denominator = self.denomi * other.denomi
+        new_fraction = Fraction(new_nominator, new_denominator)
+        return Fraction.reduce_fraction(new_fraction)
diff --git a/week2/4-Fractions/p04_test_anImmutableFraction.py b/week2/4-Fractions/p04_test_anImmutableFraction.py
new file mode 100644
index 0000000..6a0e824
--- /dev/null
+++ b/week2/4-Fractions/p04_test_anImmutableFraction.py
@@ -0,0 +1,78 @@
+import unittest
+
+from p04_anImmutableFraction import Fraction
+
+
+class TestFraction(unittest.TestCase):
+
+    def setUp(self):
+        self.a = Fraction(1, 2)
+        self.b = Fraction(2, 4)
+        self.c = Fraction(1, 2)
+        self.d = Fraction(5, 6)
+        self.e = Fraction(2, 2)
+        self.f = Fraction(7, 13)
+        self.g = Fraction(4, 18)
+
+    def test_constructor(self):
+        self.assertIsInstance(self.a, Fraction)
+
+    def test_to_str1(self):
+        self.assertEqual(str(self.a), "1 / 2")
+
+    def test_to_str2(self):
+        self.assertEqual(str(self.e), '1')
+
+    def test_eq(self):
+        self.assertTrue(self.a == self.c)
+        self.assertTrue(self.a == self.b)
+
+    def test_eq_false(self):
+        self.assertFalse(self.a == self.d)
+
+    def test_reduce_fraction(self):
+        self.assertEqual(Fraction.reduce_fraction(self.b), Fraction(1, 2))
+
+    # 1 / 2 + 2 / 4 =
+    def test_add1(self):
+        self.assertEqual(self.a + self.b, Fraction(1, 1))
+
+    # 1 / 2 + 5 / 6 =
+    def test_add2(self):
+        self.assertEqual(self.a + self.d, Fraction(4, 3))
+
+    # 1 / 2 + 0 =
+    def test_add3(self):
+        self.assertEqual(self.a + 0, Fraction(1, 2))
+
+    # 1 / 2 + 2 =
+    def test_add4(self):
+        self.assertEqual(self.a + 2, Fraction(5, 2))
+
+    # 1 / 2 - 1 / 2 =
+    def test_sub1(self):
+        self.assertTrue(self.a - self.b, Fraction(6, 6))
+
+    # 1 / 2 - 5 / 6 =
+    def test_sub2(self):
+        self.assertEqual(self.a - self.d, Fraction(-1, 3))
+
+    # 1 / 2 * 1 / 2 =
+    def test_multiplication1(self):
+        self.assertEqual((self.a * self.b), Fraction(1, 4))
+
+    # 1 / 2 * 5 / 6 =
+    def test_multiplication2(self):
+        self.assertEqual((self.a * self.d), Fraction(5, 12))
+
+    # 7 / 13 * 4 / 18 =
+    def test_multiplication3(self):
+        self.assertEqual(self.f * self.g, Fraction(14, 117))
+
+    # 1 / 2 * 5 =
+    def test_multiplication4(self):
+        self.assertEqual(self.a * 5, Fraction(5, 2))
+
+
+if __name__ == "__main__":
+    unittest.main()