Creating Unique IDs of points in order from west to east

Question

I have a dataset with over 1000s points. I am wondering if I am able to give each point a unique ID starting from west to east.

I am using ArcMap 10.6. Is there a way to do this in ArcMap?

Answer 1

First, to be sure POINT_X has no duplicate values, run next two lines in Python console.

# change layer_name
x_values = [row[0] for row in arcpy.da.SearchCursor("layer_name", "POINT_X")]
len(x_values) == len(set(x_values)) # output should be True

If POINT_X has no duplicate values you can use the following script in Field Calculator.

• Open Field Calculator (by right click on seq field)

• Populate the parameters as in the image using the following script. (Don't forget to change layer_name in the script)

  x_values = [row[0] for row in arcpy.da.SearchCursor("layer_name", "POINT_X")]
  x_values.sort(reverse=True)
  
  def add_unique_ids(x):
      global x_values   
      i = x_values.index(x)   
      return i
  

• And call the method.

  add_unique_ids(!POINT_X!)
  

The main limitation is that features with the same POINT_X get the same seq value. I couldn't figure it out yet.