Added Exercise 4

ex_01_04.py

@@ -0,0 +1,65 @@
+#!/usr/bin/python3
+
+from util.io import readvalue
+
+def positive_float(v):
+	x = float(v)
+	if(x <= 0):
+		raise ValueError("{} is a non-positive float".format(v))
+	return x
+
+
+class Circle(object):
+	__slots__ = ["x", "y", "radius"]
+
+	def __init__(self, x, y, radius):
+		self.x = x
+		self.y = y
+		self.radius = radius
+
+	def has_intersection(self, other):
+		if(not isinstance(other, Circle)):
+			raise TypeError("cannot calculate intersection of Circle and {}".format(type(other)))
+
+		distance = ((self.x - other.x)**2 + (self.y - other.y)**2)**0.5
+		if(distance < self.radius + other.radius):
+			return True
+		return False
+
+	def __contains__(self, other):
+		if(not isinstance(other, Circle)):
+			raise TypeError("cannot calculate wether {} is in Circle".format(type(other)))
+
+		distance = ((self.x - other.x)**2 + (self.y - other.y)**2)**0.5
+
+		if(other.radius + distance < self.radius):
+			return True
+		return False
+	
+	@staticmethod
+	def read_Circle():
+		radius = readvalue("radius> ", positive_float)
+		x = readvalue("x> ", float)
+		y = readvalue("y> ", float)
+
+		return Circle(x, y, radius)
+
+
+if( __name__ == "__main__"):
+	print("Create Circle 1:")
+	c1 = Circle.read_Circle()
+	print("Create Circle 2:")
+	c2 = Circle.read_Circle()
+
+	print("\n")
+
+	if(c1.has_intersection(c2)):
+		print("The two circles have an intersection.")
+	else:
+		print("The two circles have no intersection.")
+
+	if(c2 in c1):
+		print("Circle 1 contains Circle 2")
+	if(c1 in c2):
+		print("Circle 2 contains Circle 1")
+