how to test if linear exists with a buffer with ArcPy

Question

I have a layer with several linear that I want to integrate into a database. But before integrating it, I have to test if the linear already exists or not. There is a lot of linear in the database so to make the processing faster I want to delimit the area I want to integrate first and test only on that area.
The rule I want to implement is to create a buffer around the incoming layer and to check if the linear in the database is 90% in the buffer zone. If it is the case then we consider that the incoming linear is a duplicate. If not, we integrate it.

I am looking for an algorithm that will allow me to save processing time and be as accurate as possible:

incom_undergroundspan = "AX_UNDERGROUNDSPAN"
db_undergroundspan = "ND_UNDERGROUNDSPAN

buffer = arcpy.Buffer_analysis(incom_undergroundspan, "test_buffer2", 5, "FULL", "ROUND")
#select only the linear contained at 90% in the buffer zone and delete the rest

Answer 1

Use the Clip tool to get the geometry of the lines within the buffer, then compare the length of the clipped lines with the original lines to get your percentage within the buffer