topic Re: Use inline variable for a field name in Select Layer by Attribute ----HELP!!!! in ArcGIS Pro Questions

Use inline variable for a field name in Select Layer by Attribute ----HELP!!!!

HussainMalik1 — Tue, 16 Feb 2021 08:04:33 GMT

Hi,

How can I use an Inline Variable as a field name in Select Layer by Attribute in code block.

I want to get the field name from multivalued variable table rather than from Attribute Table. In Select Layer by Attribute Year and %VariableFieldName% value in "where clause" comes from string Var2 as shown in the Image.

def x(Var2): for i in Var2.split(";"): a,b=shlex.split(i) with arcpy.EnvManager(scratchWorkspace=r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb", workspace=r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb"): lyr = arcpy.management.SelectLayerByAttribute(r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb\IDEAL_SHAPE_TimeSeries_Feb14_V1", "NEW_SELECTION", f"Year = {a} And %VariableFieldName% >0, None) Data type : Long

I will really appreciate your help

Thanks

Re: Use inline variable for a field name in Select Layer by Attribute ----HELP!!!!

DanPatterson — Tue, 16 Feb 2021 12:25:25 GMT

This needs to be fixed...

f"Year = {a} And %VariableFieldName%

you are missing a " and, And is and

try something along the lines of

'"Year" = {} and "{}" > 0'.format(a, v)

where 'a' is the year and v is the variable

Also packing your code into a one-liner isn't very useful

Code formatting ... the Community Version - GeoNet, The Esri Community

split this up

s_ws = r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb" ws = r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb" with arcpy.EnvManager(scratchWorkspace=s_ws,workspace=ws): # etc

to make it readable

Re: Use inline variable for a field name in Select Layer by Attribute ----HELP!!!!

HussainMalik1 — Tue, 16 Feb 2021 17:18:03 GMT

Thanks @DanPatterson for the help .

I am getting the following Syntax Error message

ERROR 000539: File "<string>", line 6 SyntaxError: f-string: empty expression not allowed Failed to execute (Calculate Value Multiple Fields).

Please do check attached image for detail geoprocessing message

Thanks

Hussain

Re: Use inline variable for a field name in Select Layer by Attribute ----HELP!!!!

DanPatterson — Tue, 16 Feb 2021 17:22:45 GMT

A screengrab of the code isn't going to help.

It also appears that you didn't take my suggestion of making the existing code more readable .

I can't tell if you fixed the error I pointed out in your expression

Re: Use inline variable for a field name in Select Layer by Attribute ----HELP!!!!

HussainMalik1 — Tue, 16 Feb 2021 17:58:50 GMT

@DanPatterson

I changed it according to your advice and it does looks better though.

Expression: x(("%VT%") import shlex s_ws = r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb" ws = r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb" tbl= "IDEAL_SHAPE_TimeSeries_Feb14_V1" def x(VT): for i in VT.split(";"): a,b,c=shlex.split(i) with arcpy.EnvManager(scratchWorkspace=s_ws, workspace=ws): lyr = arcpy.management.SelectLayerByAttribute(tbl, "NEW_SELECTION", f'"Year" = {} and "{}">0'.format(a,b) , None) x = arcpy.management.GetCount(lyr)

ERROR 000539: File "<string>", line 9 SyntaxError: f-string: empty expression not allowed Failed to execute (Calculate Value Multiple Fields).

I am also trying to figure out the next part of this code where I have to calculate a new field and use the values from same field that I select in the code above (string "b" in this example ). Correct me if I am wrong if SeachCursor would be a good approach for that.

Re: Use inline variable for a field name in Select Layer by Attribute ----HELP!!!!

DanPatterson — Tue, 16 Feb 2021 18:33:00 GMT

throw in a print statement, it apparently doesn't see a or b

Re: Use inline variable for a field name in Select Layer by Attribute ----HELP!!!!

HussainMalik1 — Wed, 17 Feb 2021 04:52:38 GMT

So I have changed the SelectLayerByAttribute and put the values (a and b) from string VT1 in curly brackets. where {a} = Year field and {b} = !ELECUSE_Large_Schools! field in attribute table.

Code below is a snippet from model builder Python in Arcpro.

Now this runs with no error message but it only selects the last part of the VT1 string.

How can i make it run for the whole VT1 variable?

import shlex s_ws = r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb" ws = r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb" tbl= "IDEAL_SHAPE_TimeSeries_Feb14_V1" def x(VT1): for i in VT1.split(";"): a,b,c= shlex.split(i) with arcpy.EnvManager(scratchWorkspace=s_ws, workspace=ws): lyr= arcpy.management.SelectLayerByAttribute(tbl, "NEW_SELECTION", f'"Year" = {a} and "{b}">0'.format(a,b),None) x= arcpy.management.GetCount(lyr) def Model5(VT1=[[2020, "ELECUSE_Large_Schools", 0.2], [2040, "ELECUSE_Large_Schools", 0]]): # Model 4 # To allow overwriting outputs change overwriteOutput option to True. arcpy.env.overwriteOutput = False # Process: Calculate Value (Calculate Value) () if VT1: Value = x("VT1") if __name__ == '__main__': # Global Environment settings with arcpy.EnvManager(scratchWorkspace=r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb", workspace=r"D:\GBT_R_Drive\GBT_GIS\ICEMIgdb\ICEM\BldgEmission.gdb"): Model5(*argv[1:])

Thanks