I am trying to convert a code from Mathemtica to Python and I am trying to understand what the following expression does: I have df.txt that has the following structure:
{0.01, 0.01, 0.} 1.00000000002e-10
{0.01, 0.01, 0.05} 2.6020872669e-10
{0.01, 0.01, 0.1} 6.2612393705e-10
{0.01, 0.01, 0.15} 1.40324498972e-9

Clear[df, iJDP]
df = ToExpression[Import[NotebookDirectory[] <> "df.txt", "TSV"]];
iJDP = Interpolation[Map[{#[[1]], #[[2]]} &, df], 
   InterpolationOrder -> {1, 1, 1}, Method -> "Spline"];

I don't understand if 1 and 2 correspond to the first cluster and the second value, or something else. Furthermore I have this step
x,y,z are the columns of the df dataset

a = If[rho < 1, 
   z /. FindRoot[iJDP[x, y, z] == rhs, {R2, 0.5, 0, 1}], 1];

In this case what is looking for iJDP?

Thanks