(self)
return 0.5 * (self.left + self.right)
Return the midpoint of the interval. Take care when the left or
        right sides are infinite.
Return the midpoint of the interval. Take care when the left or
        right sides are infinite.
Return the midpoint of the interval . Take care when the left or right sides are infinite .
def mid(self):
        """Return the midpoint of the interval. Take care when the left or
        right sides are infinite.

        """
        return 0.5 * (self.left + self.right)
def mid ( self ) : return 0.5 * ( self . left + self . right )