Question: I am looking for a way to calculate sequential numbers in points feature along line.

I've got polygon 1 feature intersected with other layer of polygons. Then I extract points from the intersection, and get points1 layer. After that I extract the points from the vertices of polygon (1) (points2 layer). Also I create points along line by distance (points3). Then I merege all layers together (points1 + points2 + points3). Then I want to give them a sequential numbers going up along the border of polygon 1 by order.

My goal is to add points along the line that will be in ascending order, in favor of an orientation map for contractors in the field. 

Is there a way to calculate it by field calculator?

I am using Arcmap 10.6.

Answer: 
If you have polylines stored in shapefile and call them "LINES" in your mxd table of content, below field calculator expression will populate numerical field of your points table by distance from relevant line start:

```
g=arcpy.Geometry()
geomList=arcpy.CopyFeatures_management("LINES",g)
def Chainage(id,shp):
 geom=geomList[id]
 L=geom.measureOnLine (shp.firstPoint)
 return L
#------------
Chainage( !NEAR_FID! , !Shape! )

```
Thank you,
I've been able to use your code snippet, along with another snippet to create a sequence of numbers:

```
counter = 1
rows = arcpy.UpdateCursor("Cities","","","NAME; SortFld", "NAME")
for row in rows:
row.SortFld = counter
  counter = counter + 1
  rows.updateRow(row)

```

I found this in another discussion:
[Sort Column and Sequentially Number Separate Column](https://gis.stackexchange.com/questions/191188/sort-column-and-sequentially-number-separate-column)