Select from user input variable

NoahHuntington · ‎09-10-2012

Please help. Unable to make selection.

Here is what I have....

# Model selects parcel from user input import arcpy  # Assign variable to the feature class featureClass = "G:\\PRAD\\PRAD_v10.1.gdb\\tax_acct"  # Assign variable to users input input = arcpy.GetParameterAsText(0)  # Make a feature layer from feature class arcpy.MakeFeatureLayer_management(featureClass, "layer")       # Apply a selection to the feature layer  arcpy.SelectLayerByAttribute_management("layer", "NEW_SELECTION", '"'+str(input)+'"')

NoahHuntington · ‎09-10-2012

Well first of all you don't have feature classes in your TOC, you have layers pointing to your feature classes on disk. These are the objects you make selections on, you cannot make selections on feature classes.

Try running this as your script. You could also add another input parameter to select the layer manually.

import arcpy  def main():     arcpy.AddMessage("Starting")      # Get and set variables     job_num = arcpy.GetParameterAsText(0)     layer_name = "tax_acct"     df_name = "Layers"      arcpy.AddMessage(job_num)      # Define mxd, df and lyr objects     mxd = arcpy.mapping.MapDocument("CURRENT")     df = arcpy.mapping.ListDataFrames(mxd, df_name)[0]     lyr = arcpy.mapping.ListLayers(mxd, layer_name, df)[0]      arcpy.AddMessage(lyr.name)      # Create where clause for selection     query = "Job_Num = '%s'" % (job_num)      arcpy.AddMessage(query)      arcpy.SelectLayerByAttribute_management(lyr, "NEW_SELECTION", query)      # Get number of selected features     selection = int(arcpy.GetCount_management(layer_name).getOutput(0))      arcpy.AddMessage("%s features selected" % (selection))      # Set df extent to layer selection     df.extent = lyr.getSelectedExtent()     arcpy.RefreshActiveView()      arcpy.AddMessage("Completed")  main()

That was perfect!!! Your fast too! Just a couple questions? What was going on with the addmessages methods? Also some of these features have 1, 2, or 3 possible job numbers associated with them, as in fields Job_Num2, Job_Num3, so on.... Would there be a way add multiple fields to the query? Job_Num, or Job_Num2, or Job_Num3..

View solution in original post

MathewCoyle · ‎09-10-2012

The last line shouldn't be indented. Are you getting a syntax error or some other error? Also, what is the value of your input variable? Try using AddMessage to see if it is passing how you would expect it to.

NoahHuntington · ‎09-10-2012

The last line shouldn't be indented. Are you getting a syntax error or some other error? Also, what is the value of your input variable? Try using AddMessage to see if it is passing how you would expect it to.

The input is a 6 or 7 digit text field found in the feature class. The script is run as a tool where the input parameter is set to string. Here is what I currently have...

# Selects from user input in tool dialog.  

import arcpy

# Get the layer.
featureClass = "G:\\PRAD\\PRAD_v10.1.gdb\\tax_acct"
input = arcpy.GetParameterAsText(0)

try:
    # Make a feature layer from feature class
    arcpy.MakeFeatureLayer_management(featureClass, "layer")
    
    # Apply a selection to the feature layer
    arcpy.SelectLayerByAttribute_management("layer", "NEW_SELECTION", '"'+str(input)+'"')

except:
    print arcpy.GetMessages()

MathewCoyle · ‎09-10-2012

You need to print out the actual value of the variable the tool is reading to make sure it is a valid query.

NoahHuntington · ‎09-10-2012

You need to print out the actual value of the variable the tool is reading to make sure it is a valid query.

Sorry I must be slow. I am not sure I am following you. Can I see an example?

MathewCoyle · ‎09-10-2012

Depending on your data type it could look something like this.

input = "\"CITY_NAME\" = 'Chicago'"

You can see more examples here.
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//001700000071000000

NoahHuntington · ‎09-10-2012

Depending on your data type it could look something like this.
input = "\"CITY_NAME\" = 'Chicago'"
You can see more examples here.
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//001700000071000000

Right. I can see now that something is missing. What does the syntax look like for whereclause when field name is Job_Num and variable is input. Similar to...

..."Job_Num = " + str(input))

MathewCoyle · ‎09-10-2012

This should work. You may need to add quotes around your field name, or use the add field delimiters tool to create them for dynamic data sources.

# Model selects parcel from user input
import arcpy

# Assign variable to the feature class
featureClass = "G:\\PRAD\\PRAD_v10.1.gdb\\tax_acct"

# Assign variable to users input
input = arcpy.GetParameterAsText(0)

# Make a feature layer from feature class
arcpy.MakeFeatureLayer_management(featureClass, "layer")

# Build selection query
query = "Job_Num = '%s'" % (input)  # May need change to "\"Job_Num\" = '%s'"

# Apply a selection to the feature layer
arcpy.SelectLayerByAttribute_management("layer", "NEW_SELECTION", query)

NoahHuntington · ‎09-10-2012

This should work. You may need to add quotes around your field name, or use the add field delimiters tool to create them for dynamic data sources.

# Model selects parcel from user input
import arcpy

# Assign variable to the feature class
featureClass = "G:\\PRAD\\PRAD_v10.1.gdb\\tax_acct"

# Assign variable to users input
input = arcpy.GetParameterAsText(0)

# Make a feature layer from feature class
arcpy.MakeFeatureLayer_management(featureClass, "layer")

# Build selection query
query = "Job_Num = '%s'" % (input)  # May need change to "\"Job_Num\" = '%s'"

# Apply a selection to the feature layer
arcpy.SelectLayerByAttribute_management("layer", "NEW_SELECTION", query)

This runs without error but nothing gets selected? I have tested with attributes in the Job_Num field that I have checked to exist. What do you think? Thanks again.

MathewCoyle · ‎09-10-2012

Try adding these lines at the end of your script. This will print how many features are selected, and then refresh the view to make those selections visible.

selection = int(arcpy.GetCount_management("layer").getOutput(0))
arcpy.AddMessage("%s features selected" % (selection))
arcpy.RefreshActiveView()