Add Spatial Join using Python

Luca_Schikowski

Hi there,

I am currently trying to work with python in ArcGIS Pro and I am stuck with the "Add Spatial Join"-Tool.

I got point-features (households) and lines (ducts) connected to them. I want to transfer some of the attributes from the households to the ducts feature class.

So first, I need to da a spatial join, right?

This is my code:

#code starts

import arcpy
import sys

def main():
arcpy.env.overwriteOutput = True

ducts = arcpy.GetParameterAsText(0)
houses = arcpy.GetParameterAsText(1)

try:
arcpy.AddMessage(f"Add Spatial Join:\n - Target-Layer: {ducts}\n - Join-Layer: {houses}")

arcpy.management.AddSpatialJoin(
target_features=ducts,
join_features=houses,
join_operation='JOIN_ONE_TO_ONE',
join_type='KEEP_ALL',
field_mapping='CID',
match_option='INTERSECT'
)
arcpy.AddMessage("Spatial Join Added successfully.")
except Exception as e:
arcpy.AddError(f"Error at 'Add Spatial Join': {e}")
if __name__ == "__main__":
main()

#code ends

When running this code, I get all the messages correctly and the tool finishes successfully but there is no spatial join added to my feature class. Is there an error in my code?

Thank you for your help!

Luca

Bryan_bsc

Hi Luca,

Unless your point features are exactly on the line features they won't intersect. I would try changing the match option from INTERSECT to CLOSEST. eg.

Cheers,

Bryan

Luca_Schikowski

Hi,

thank you, but the features are always directly connected.

ModyBuchbinder

Is the first parameter to the tool (ducts) a layer in pro or a FC on disk?

It must be a layer in Pro since the spatial join is on a layer and not on the real data.

You can always use the Gp tool once and then copy the code from the History window.

Luca_Schikowski

Hi,

so the code will only work, when the feature classes are actually added to the map in arc gis pro, right?

AlfredBaldenweck

Whenever you do anything involving a join or a selection on data, you need to make it a variable. otherwise, all the work gets done and then thrown into the ether.

This is my code:

#code starts

import arcpy
import sys

def main():
arcpy.env.overwriteOutput = True

ducts = arcpy.GetParameterAsText(0)
houses = arcpy.GetParameterAsText(1)

try:
arcpy.AddMessage(f"Add Spatial Join:\n - Target-Layer: {ducts}\n - Join-Layer: {houses}")

sjoin = arcpy.management.AddSpatialJoin(
target_features=ducts,
join_features=houses,
join_operation='JOIN_ONE_TO_ONE',
join_type='KEEP_ALL',
field_mapping='CID',
match_option='INTERSECT'
)
arcpy.AddMessage("Spatial Join Added successfully.")
except Exception as e:
arcpy.AddError(f"Error at 'Add Spatial Join': {e}")
if __name__ == "__main__":
main()

#code ends

You might have to add some lines telling it to actually add to the map, but I'd start with naming it and see what happens.

Luca_Schikowski

Hi, thank you!

When running your code, an error occurs:

I could not find the reason for this error. After some research it seems to be a syntax error. But why?