title: Construct a symbolic interpolating spline through given points using SymPy
body: <p>Pretend I start with some simple dataset which is defined on R2 follows:</p>
  
  <pre><code>DataPointsDomain = [0,1,2,3,4,5]
  DataPointsRange =  [3,6,5,7,9,1]
  </code></pre>
  
  <p>With scipy I can make a lazy polynomial spline using the following:</p>
  
  <pre><code>ScipySplineObject = scipy.interpolate.InterpolatedUnivariateSpline( 
      DataPointsDomain, 
      DataPointsRange, 
      k = 1, )
  </code></pre>
  
  <p>What is the equivalent object in sympy??</p>
  
  <pre><code>SympySplineObject = ...???
  </code></pre>
  
  <p>(I want to define this object and do analytic sympy manipulation like taking integrals, derivatives,  etc... on the sympy object )</p>