From your screenshot I see you are using ArcGIS. I do not know if you have the required Info/Advanced license, but there is a Pivot Table tool that may do what you want. It can flatten one-to-many relationships in a table, and unlike the two related questions below, it actually creates new attribute fields for each of the values instead of writing them all to a single field. There are Python code samples, including stand-alone script, at the linked help page.
If you don't have access to the Pivot Table tool, or want to do it without relying on that, there are two questions with slightly different approach answers that partially solve the problem already here on GIS.SE:
Both provide code/script solutions, but both also write the values to a single field. If you want separate attributes, you would have to add some code that would then add the necessary number of new fields and split the values from the single field to their individual ones.