clean up

First_edition_2014/ebook_src/USEFUL/oop/ShapeClass.py

@@ -0,0 +1,62 @@
+#!/usr/bin/python3
+# mari von steinkirch @2013
+# steinkirch at gmail
+
+
+import math
+
+class Point(object):
+    def __init__(self, x=0, y=0): # self: object reference to the object itself
+        self.x = x  # data attribute
+        self.y = y
+	
+    def distance_from_origin(self):
+        return math.hypot(self.x, self.y)
+	
+    def __eq__(self, other):
+        return self.x == other.x and self.y == other.y
+		
+    def __repr__(self):
+        return "point ({0.x!r}, {0.y!r})".format(self)
+		
+    def __str__(self): # cannot be passed to eval
+        return "({0.x!r}, {0.y!r})".format(self)	
+	
+	
+class Circle(Point):
+    
+    def __init__(self, radius, x=0, y=0):
+        super().__init__(x,y) # creates and initializes self.x and self.y
+        self.radius = radius
+	
+    def edge_distance_from_origin(self):
+        return abs(self.distance_from_origin() - self.radius)
+	
+    def area(self):
+        return math.pi*(self.radius**2)
+		
+    def circumference(self):
+        return 2*math.pi*self.radius
+	
+    def __eq__(self, other): # let us avoid infinite recursion
+        return self.radius == other.radius and super().__eq__(other)	
+	
+    def __repr__(self):
+        return "circle ({0.radius!r}, {0.x!r})".format(self)
+		
+    def __str__(self):
+        return repr(self)
+        
+        
+ 
+
+if __name__ == '__main__':
+    a = Point(3,4)
+    print(a.distance_from_origin())
+    c = Circle(3,2,1)
+    print(c)
+    print(c.circumference())
+    print(c. edge_distance_from_origin())
+
+
+