topic Re: Select from user input variable in Python Questions

Select from user input variable

NoahHuntington — Mon, 10 Sep 2012 15:27:43 GMT

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)+'"')

Re: Select from user input variable

MathewCoyle — Mon, 10 Sep 2012 15:38:42 GMT

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.

Re: Select from user input variable

NoahHuntington — Sun, 12 Dec 2021 02:48:50 GMT

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()

Re: Select from user input variable

MathewCoyle — Mon, 10 Sep 2012 16:03:14 GMT

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

Re: Select from user input variable

NoahHuntington — Mon, 10 Sep 2012 16:07:28 GMT

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?

Re: Select from user input variable

MathewCoyle — Mon, 10 Sep 2012 16:11:40 GMT

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

Re: Select from user input variable

NoahHuntington — Mon, 10 Sep 2012 17:10:52 GMT

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))

Re: Select from user input variable

MathewCoyle — Sun, 12 Dec 2021 02:48:52 GMT

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)

Re: Select from user input variable

NoahHuntington — Sun, 12 Dec 2021 02:48:55 GMT

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.

Re: Select from user input variable

MathewCoyle — Sun, 12 Dec 2021 02:48:58 GMT

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()

Re: Select from user input variable

NoahHuntington — Sun, 12 Dec 2021 02:49:00 GMT

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()

I can see 1 selected in results window but still no effect on dataframe? See attached...

Re: Select from user input variable

NoahHuntington — Sun, 12 Dec 2021 02:49:03 GMT

[ATTACH=CONFIG]17579[/ATTACH]

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()

I can see 1 selected in results window but still no effect on dataframe? See attached...

Re: Select from user input variable

MathewCoyle — Mon, 10 Sep 2012 18:22:41 GMT

[ATTACH=CONFIG]17579[/ATTACH]

I can see 1 selected in results window but still no effect on dataframe? See attached...

That is because you create a temporary layer called "layer" that you are basing your selections on. I don't see that layer in your TOC.

Maybe you should describe what you want to accomplish since it looks like you are going about this the wrong way.

Re: Select from user input variable

NoahHuntington — Mon, 10 Sep 2012 18:25:12 GMT

That is because you create a temporary layer called "layer" that you are basing your selections on. I don't see that layer in your TOC.

Maybe you should describe what you want to accomplish since it looks like you are going about this the wrong way.

I am trying to create a simple tool to collect user input and zoom to selected feature. ideally would like to select from fc in toc. Any suggestions?

...maybe a search cursor?

Re: Select from user input variable

MathewCoyle — Sun, 12 Dec 2021 02:49:06 GMT

I am trying to create a simple tool to collect user input and zoom to selected feature. ideally would like to select from fc in toc. Any suggestions?

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()

Re: Select from user input variable

NoahHuntington — Mon, 10 Sep 2012 18:54:30 GMT

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..

Re: Select from user input variable

MathewCoyle — Sun, 12 Dec 2021 02:49:09 GMT

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..

The addmessages are there just to check your variables to make sure they are what you are expecting. They are unnecessary for the script itself and more for trouble shooting.

If you are selecting from multiple fields, are they all the same value from these fields? Or do you want unique values from each field?
Eg

Job_Num = "first" and Job_Num2 = "first"
# or
Job_Num = "first" and Job_Num2 = "second"

Re: Select from user input variable

NoahHuntington — Sun, 12 Dec 2021 02:49:12 GMT

The addmessages are there just to check your variables to make sure they are what you are expecting. They are unnecessary for the script itself and more for trouble shooting.

If you are selecting from multiple fields, are they all the same value from these fields? Or do you want unique values from each field?
Eg
Job_Num = "first" and Job_Num2 = "first"
# or
Job_Num = "first" and Job_Num2 = "second"

They exist b/c we have revisited parcels sometimes multiple times each with a new job number. Added field to table to handle new job number. I am not sure the following is correct, where should this query take place.


    # Get and set variables
    Job_Num = "first" and Job_Num2 = "second" = arcpy.GetParameterAsText(0)
    layer_name = "tax_acct"
    df_name = "Layers"

Re: Select from user input variable

MathewCoyle — Sun, 12 Dec 2021 02:49:14 GMT

For each field you will need a new parameter added to your tool. There are a couple ways to go about it, and it gets a little more complicated if you want it to be dynamic (eg a user can select any number of fields to put in the query).

    job_num = arcpy.GetParameterAsText(0)
    job_num2 = arcpy.GetParameterAsText(1)
    job_num3 = arcpy.GetParameterAsText(2)
    ...
    # Create where clause for selection
    query = ""
    query_list = [("Job_Num", job_num), ("Job_Num2", job_num2), ("Job_Num3", job_num3)]
    for field_name, variable in query_list:
        if query == "":                                              
            query = "%s = '%s'" % (field_name, variable)            
        else:                                                        
            query = query + " and %s = '%s'" % (field_name, variable)

Something like that should get you on track. May require some tinkering to make it work for you.

Re: Select from user input variable

NoahHuntington — Sun, 12 Dec 2021 02:49:17 GMT

For each field you will need a new parameter added to your tool. There are a couple ways to go about it, and it gets a little more complicated if you want it to be dynamic (eg a user can select any number of fields to put in the query).
    job_num = arcpy.GetParameterAsText(0)
    job_num2 = arcpy.GetParameterAsText(1)
    job_num3 = arcpy.GetParameterAsText(2)
    ...
    # Create where clause for selection
    query = ""
    query_list = [("Job_Num", job_num), ("Job_Num2", job_num2), ("Job_Num3", job_num3)]
    for field_name, variable in query_list:
        query = query + "%s = '%s' " % (field_name, variable)
Something like that should get you on track. May require some tinkering to make it work for you.

Ok. I will see what I can do with that. Thanks for all your help!