Interpolation and Peak Finding

interp1d

Perhaps the most commonly used interpolating function in python is scipy.interpolate.interp1d.  The default option is linear interpolation but for sparsely separated data a cubic spline is often preferable. See the interp1d manual page for additional options and details.
Here is an example of how to use interp1d to construct a cubic spline interpolation of sparse data.
First, import the necessary python packages and data: