I am trying to get ModelBuilder to create a route for each row in a csv file. Each row has one start and stop locations (Point A and Point B). I need to add both start and stop locations to a network layer to create a route. I then need to delete these stops, and iterate back through, creating a route for each record between each start and stop point. In the Add Locations tool help, I read that the Append Parameter might be what I need to use. In the tool dialog box, there is just a checkbox, but in the Python reference it says

• APPEND—Adds the new network analysis objects to the existing set of objects in the selected sublayer. • CLEAR—Deletes the existing network analysis objects and replaces them with the new objects.

I think I need to do both Append and Clear actions to get what I am trying to achieve but it is just a checkbox in ModelBuilder.

Will I need to use Python code to be able to append, then clear, stops in an iterator model?

I am not very strong writing Python Code and was hoping to use ModelBuilder to get what I need.