Added Circle Class

students/ChiHo/session08/circle.py

@@ -0,0 +1,152 @@
+# Student: Chi Kin Ho
+# Date: Wednesday, March 2, 2016
+
+import math
+
+
+class Circle(object):
+
+    def __init__(self, the_radius):
+        # Keep track of the radius of the circle.
+        self._radius = the_radius
+        # Calculate the diameter of the circle.
+        self._diameter = self._radius * 2
+
+    # alternate constructor
+    @classmethod
+    def from_diameter(cls, the_diameter):
+        return cls(the_diameter / 2)
+
+    @property
+    def radius(self):
+        return self._radius
+
+    @radius.setter
+    def radius(self, the_radius):
+        if the_radius is not None:
+            # Update the radius.
+            self._radius = the_radius
+            # Update the diameter.
+            self._diameter = self._radius * 2
+
+    @property
+    def diameter(self):
+        return self._diameter
+
+    # Set the diameter of the circle and update its radius.
+    @diameter.setter
+    def diameter(self, the_diameter):
+        if the_diameter is not None:
+            # Update the diameter.
+            self._diameter = the_diameter
+            # Update the radius.
+            self._radius = self._diameter / 2
+
+    @property
+    def area(self): # area property
+        # Return the area of the circle: pi * radius * radius
+        return math.pi * self._radius * self._radius
+
+    def __repr__(self):
+        return 'Circle({})'.format(self._radius)
+
+    def __str__(self):
+        return 'Circle({})'.format(self._radius)
+
+    # + operator overloading
+    def __add__(self, other):
+        return Circle(self._radius + other.radius)
+
+    # augmented assignment operator += overloading
+    def __iadd__(self, other):
+        self = self + other
+        return self
+
+    # * operator overloading
+    def __mul__(self, other):
+        return Circle(self._radius * other)
+
+    # augmented assignment operator *= overloading
+    def __imul__(self, other):
+        self = self * other
+        return self
+
+    # reflected numerics for the * operator overloading
+    def __rmul__(self, other):
+        return self * other
+
+    # > operator overloading
+    def __lt__(self, other):
+        return self._radius < other.radius
+
+    # >= operator overloading
+    def __le__(self, other):
+        return self._radius <= other.radius
+
+    # > operator overloading
+    def __gt__(self, other):
+        return self._radius > other.radius
+
+    # >= operator overloading
+    def __ge__(self, other):
+        return self._radius >= other.radius
+
+    # == operator overloading
+    def __eq__(self, other):
+        return self._radius == other.radius
+
+# Steps 1, 2, 3, and 3:
+
+c = Circle(4)
+print(c.radius)
+print(c.diameter)
+print(c.area)
+
+# Step 5
+
+c = Circle.from_diameter(20)
+print(c.diameter)
+print(c.radius)
+
+# Step 6
+
+print(repr(c))
+d = eval(repr(c))
+print(d)
+print(c)
+
+# Step 7
+
+c1 = Circle(2)
+c2 = Circle(4)
+print(c1 + c2)
+print(c2 * 3)
+print(3 * c2)
+
+# Step 8:
+
+print(c1 > c2)
+print(c1 < c2)
+print(c1 == c2)
+c3 = Circle(4)
+print(c2 == c3)
+
+circles = [Circle(6), Circle(7), Circle(8), Circle(4), Circle(0), Circle(2), Circle(3), Circle(5), Circle(9), Circle(1)]
+print(circles)
+circles.sort()
+print(circles)
+
+
+# Step 8: Optional Features
+
+print(3 * c2 == c2 * 3)
+
+a_circle = Circle(4)
+another_circle = Circle(9)
+a_circle += another_circle
+print(a_circle)
+print(another_circle)
+
+a_circle = Circle(4)
+a_circle *= 2
+print(a_circle)