It would help us understand your question if you provide an example file.
Generally in python if you have a list of objects you can get the nth element in the list using square brackets. Eg my_list = (10,42,3,4,1)
Then my_list[1] will return 42
You also need to ensure that your python component has list access. Right click on the input parameter (x) and set list access (it is item by default). With list access x[0] will return the first point. With item access x[0] will return the x coordinate of each point