topic Getting a spatial reference from a script tool parameter in Python Questions

Getting a spatial reference from a script tool parameter

NeilAyres — Tue, 10 Mar 2015 14:00:46 GMT

Been stuck on this for a while this afternoon.

I have been writing a script tool which loads some data from a table in a db.

I needed to then set the spatial reference of the coordinates.

So, in my script I had :

SR = arcpy.GetParameterAsText(1)

And in the tool properties, this is set to a Coordinate System data type. So you get the nice pull down list of the available coordinate systems.

However, this returns a text representation of the prj, not a spatial reference object.

Then I tried to do this :

SR = arcpy.SpatialReference(arcpy.GetParameterAsText(1))

But you get an error because SR objects can only be created using :

1. Get them from a describe object

2. The WKID of the SR

3. A path to a projection file.

You cannot use a text string.

The answer turned out to be :

SRtxt = arcpy.GetParameterAsText(1)

SR = arcpy.SpatialReference() # an empty spatial reference object

SR.loadFromString(SRtxt)

Phew....

Now on with the rest of it....

Re: Getting a spatial reference from a script tool parameter

BlakeTerhune — Tue, 10 Mar 2015 16:40:26 GMT

Interesting little tidbit. Thanks for sharing.

Re: Getting a spatial reference from a script tool parameter

Luke_Pinner — Tue, 10 Mar 2015 19:30:12 GMT

Did you try arcpy.GetParameter(1) instead of GetParameterAsText? GetParameter returns the parameter as an object instead of a string.

Re: Getting a spatial reference from a script tool parameter

NeilAyres — Wed, 11 Mar 2015 05:32:33 GMT

I did try GetParameter, same result, it doesn't return a SR object, but a string!

I looked and looked through the documentation and found no pointers how to do this.

If the esri folk are listening, perhaps something should be in in the help files on how to do this.

My solution works, but is there another way to do it?

Re: Getting a spatial reference from a script tool parameter

NeilAyres — Wed, 11 Mar 2015 05:36:25 GMT

Oh, and another thing...

How do you get the advanced editor when starting a new thread so that you can do the code formatting correctly?

Re: Getting a spatial reference from a script tool parameter

XanderBakker — Wed, 11 Mar 2015 05:41:33 GMT

If you start a new discussion you should already be in the advanced editor.

Re: Getting a spatial reference from a script tool parameter

XanderBakker — Sat, 11 Dec 2021 07:48:17 GMT

... with respect to the coordinate system, remember that coordinate system and spatial reference are not the same. Look at the following tool, where a coordinate system and a spatial reference can be specified (both using the same interface!):

If the script for this tool is:

import arcpy
crdsys_astext = arcpy.GetParameterAsText(0)
crdsys_assobject = arcpy.GetParameter(0)
sr_astext = arcpy.GetParameterAsText(1)
sr_assobject = arcpy.GetParameter(1)

arcpy.AddMessage("crdsys_astext  : {0}".format(crdsys_astext))
arcpy.AddMessage("crdsys_asobject: {0}".format(crdsys_assobject))
arcpy.AddMessage("sr_astext      : {0}".format(sr_astext))
arcpy.AddMessage("sr_asobject    : {0}".format(sr_assobject))

then this would output:

Start Time: Tue Mar 10 22:55:26 2015

Running script Script...

crdsys_astext : PROJCS['RD_New',GEOGCS['GCS_Amersfoort',DATUM['D_Amersfoort',SPHEROID[' ... etc

crdsys_asobject: PROJCS['RD_New',GEOGCS['GCS_Amersfoort',DATUM['D_Amersfoort',SPHEROID[' ... etc

sr_astext : PROJCS['RD_New',GEOGCS['GCS_Amersfoort',DATUM['D_Amersfoort',SPHEROID[' ... etc

sr_asobject : <geoprocessing spatial reference object object at 0x181E6E78>

Completed script Script...

So, to get the sr object, you should define the parameter as spatial reference and read it as object, not as text.

Re: Getting a spatial reference from a script tool parameter

NeilAyres — Sat, 11 Dec 2021 07:48:19 GMT

Xander,

see this..

My code

# test spatial reference
import sys, os
import arcpy
SR = arcpy.SpatialReference(arcpy.GetParameter(0))
msg = "Coord sys is {}".format(SR.name)
print msg
arcpy.AddMessage(msg)

Re: Getting a spatial reference from a script tool parameter

XanderBakker — Wed, 11 Mar 2015 06:16:44 GMT

... and if you change the definition of the parameter type to spatial reference (instead of coordinate system)?

Re: Getting a spatial reference from a script tool parameter

NeilAyres — Wed, 11 Mar 2015 09:24:10 GMT

Did that, still doesn't work.

If you look at your code above, you are printing the contents of the variable.

Its still not an SR object.

Re: Getting a spatial reference from a script tool parameter

DanPatterson_Retired — Sat, 11 Dec 2021 07:48:22 GMT

Get parameter should work,

Try your procedure from the command line, which necessitates reading from an input file

And to get the advanced syntax, you have to click on the title of the thread and go to the actual thread itself and NOT reply from your inbox...at least in IE.

>>> import arcpy
>>> input_shp = 'c:/!Scripts/Shapefiles/AOI_mtm9.shp'
>>> desc = arcpy.Describe(input_shp)
>>> SR = desc.spatialReference
>>> SR
<geoprocessing spatial reference object object at 0x089330E0>
>>> SR_PCSCode = SR.PCSCode
>>> print('Spatial Reference {}'.format(SR.name))
Spatial Reference NAD_1983_CSRS_MTM_9
>>>

Re: Getting a spatial reference from a script tool parameter

NeilAyres — Wed, 11 Mar 2015 11:40:58 GMT

Dan,

I know I can get a SR object from a describe of a feature.

The point here is to set a SR from a script tool parameter.

It seems the way to do it is as outlined in my first post.

But I am very open to alternative suggestions.

Perhaps someone from esri could advise how this is done, and put something in the help files to illustrate this.

Re: Getting a spatial reference from a script tool parameter

XanderBakker — Sat, 11 Dec 2021 07:48:24 GMT

OK, let's make it more visual. I change the code to:

import arcpy
crdsys_astext = arcpy.GetParameterAsText(0)
crdsys_assobject = arcpy.GetParameter(0)
sr_astext = arcpy.GetParameterAsText(1)
sr_assobject = arcpy.GetParameter(1)

if hasattr(crdsys_astext, "name"):
    arcpy.AddMessage("crdsys_astext.name  : {0}".format(crdsys_astext.name))
if hasattr(crdsys_assobject, "name"):
    arcpy.AddMessage("crdsys_asobject.name: {0}".format(crdsys_assobject.name))
if hasattr(sr_astext, "name"):
    arcpy.AddMessage("sr_astext.name      : {0}".format(sr_astext.name))
if hasattr(sr_assobject, "name"):
    arcpy.AddMessage("sr_asobject.name       : {0}".format(sr_assobject.name))
    arcpy.AddMessage("sr_asobject.factoryCode: {0}".format(sr_assobject.factoryCode))

The result being:

Start Time: Wed Mar 11 08:39:03 2015
Running script Script...
sr_asobject.name    : RD_New
Completed script Script...
Succeeded at Wed Mar 11 08:39:03 2015 (Elapsed Time: 0,07 seconds)

So, the only correct and intended way of doing this is using a spatial reference parameter type and reading it as an object. BTW, I'm using 10.2.2 for this demo code. What version are you using?

Re: Getting a spatial reference from a script tool parameter

NeilAyres — Thu, 12 Mar 2015 14:04:21 GMT

Xander,

okay, I see what you are doing.

And, yes, if I set the Data Type to Spatial Reference & use GetParameter

There is no need to use arcpy.SpatialReference on the input variable, because it already is a SR object.

Thanks,

using v10.2.2