ch06

ch06/oop/multiple.inheritance.py

@@ -0,0 +1,74 @@
+# oop/multiple.inheritance.py
+class Shape:
+    geometric_type = 'Generic Shape'
+
+    def area(self):  # This acts as placeholder for the interface
+        raise NotImplementedError
+
+    def get_geometric_type(self):
+        return self.geometric_type
+
+
+class Plotter:
+
+    def plot(self, ratio, topleft):
+        # Imagine some nice plotting logic here...
+        print('Plotting at {}, ratio {}.'.format(
+            topleft, ratio))
+
+
+class Polygon(Shape, Plotter):  # base class for polygons
+    geometric_type = 'Polygon'
+
+class RegularPolygon(Polygon):  # Is-A Polygon
+    geometric_type = 'Regular Polygon'
+
+    def __init__(self, side):
+        self.side = side
+
+
+class RegularHexagon(RegularPolygon):  # Is-A RegularPolygon
+    geometric_type = 'RegularHexagon'
+
+    def area(self):
+        return 1.5 * (3 ** .5 * self.side ** 2)
+
+
+class Square(RegularPolygon):  # Is-A RegularPolygon
+    geometric_type = 'Square'
+
+    def area(self):
+        return self.side * self.side
+
+
+hexagon = RegularHexagon(10)
+print(hexagon.area())  # 259.8076211353316
+print(hexagon.get_geometric_type())  # RegularHexagon
+hexagon.plot(0.8, (75, 77))  # Plotting at (75, 77), ratio 0.8.
+
+square = Square(12)
+print(square.area())  # 144
+print(square.get_geometric_type())  # Square
+square.plot(0.93, (74, 75))  # Plotting at (74, 75), ratio 0.93.
+
+print(square.__class__.__mro__)
+# prints:
+# (<class '__main__.Square'>, <class '__main__.RegularPolygon'>,
+#  <class '__main__.Polygon'>, <class '__main__.Shape'>,
+#  <class '__main__.Plotter'>, <class 'object'>)
+
+
+"""
+$ python multiple.inheritance.py
+259.8076211353316
+RegularHexagon
+Plotting at (75, 77), ratio 0.8.
+144
+Square
+Plotting at (74, 75), ratio 0.93.
+(
+    <class '__main__.Square'>, <class '__main__.RegularPolygon'>,
+    <class '__main__.Polygon'>, <class '__main__.Shape'>,
+    <class '__main__.Plotter'>, <class 'object'>
+)
+"""