CoreAnimation has provided various animation APIs that can be used to accomplish the animation needs. Using UIBeizierPath and CoreAnimation APIs here I’m drawing a line and a circle using CAShapeLayer.

//Below is the function to draw a line between two points(say startPoint and endPoint)
func drawLineForMonth(from startPoint:CGPoint, to endPoint:CGPoint) -> Void {
        
        let pathAnimation: CABasicAnimation = CABasicAnimation(keyPath: "strokeEnd")
        let animDuration = 2.0 // you can change animation duration here.
        pathAnimation.duration = animDuration
        pathAnimation.fromValue = 0.0
        pathAnimation.toValue = 1.0
        let shapeLayer = CAShapeLayer()
        shapeLayer.lineWidth = 20
       	pathAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionLinear)
        let path = UIBezierPath()
        path.move(to: startPoint)
        path.addLine(to: endPoint)
        shapeLayer.path = path.cgPath
        shapeLayer.strokeColor = UIColor.red.cgColor
        self.layer.addSublayer(shapeLayer)
        shapeLayer.add(pathAnimation, forKey: "strokeEnd")
    }

//Here is a function to draw a circle having centre point 100,100
func drawCircle() -> Void {
        
        let circlePath = UIBezierPath(arcCenter: CGPoint(x: 100, y: 100), radius: CGFloat(100), startAngle: CGFloat(0), endAngle:CGFloat(M_PI * 2), clockwise: true)
        
        let shapeLayer = CAShapeLayer()
        shapeLayer.path = circlePath.cgPath
        shapeLayer.fillColor = UIColor.clear.cgColor
        shapeLayer.strokeColor = UIColor.red.cgColor
        shapeLayer.lineWidth = 3.0
        self.layer.addSublayer(shapeLayer)
        let pathAnimation: CABasicAnimation = CABasicAnimation(keyPath: "strokeEnd")
        let animDuration = 1.0
        pathAnimation.duration = animDuration
        pathAnimation.fromValue = 0.0
        pathAnimation.toValue = 1.0
        pathAnimation.timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionLinear)
        shapeLayer.add(pathAnimation, forKey: "strokeEnd")
        
    }