def __init__(self,x,y,radius):
	"""Equation construction takes centre(xValue,yValue
	and radius"""

	self.__x = float(x)
	self.__y = float(y)
	self.__radius = float(radius)

	self._o = chr(253)
	self._p = self.__radius**2
	self._q = self._checkSign(-self.__x)
	self._r = self._checkSign(-self.__y)
	self._s = "(x%s%s)%s + (y%s%s)%s = %s " % \
		   (self._q,-self.__x,self._o,self._r,-self.__y,self._o,self._p)
	self._t = self.__x**2 + self.__y**2 -self._p
	self._u = self._checkSign(self._t)
	self._v = "x%s + y%s %s %sx %s %sy %s %s = 0 " % \
		  (self._o,self._o,self._q,-self.__x*2,self._r,-self.__y*2,self._u,self._t)
Equation construction takes centre(xValue,yValue
	and radius
recipes/Python/576531_Circle/recipe-576531.py