Can't assign a Point to a Py Toolbox output parameter

09-17-2013 01:27 PM
Occasional Contributor
Below I'm trying to set a Point output parameter.  However, right after setting I check the type and it's None.  See attachment for GP results.  I've also tried GPPoint with no success.

Fundamentally it looks like only certain Types can be used for output parameters, but what others besides scalars are supported?  Seems like a simple Point should...

import arcpy

class Toolbox(object):
    def __init__(self):
        """Toolbox definition"""
        self.label = "Tools"
        self.alias = "Tools" = [GetPointTool]

class GetPointTool(object):
    def __init__(self):
        self.label = "Get me a point"
        self.description = ("Returns a simple point")
        self.canRunInBackground = True 

    def getParameterInfo(self):
        """Parameter definitions"""
        arcpy_point = arcpy.Parameter(
                        displayName = "Arcpy point",
                        name = "arcpyPoint",
                        datatype = "Point",
                        # Also tried GPPoint without success
                        parameterType = "Derived",
                        direction = "Output")

        json_point = arcpy.Parameter(
                        displayName = "JSON point",
                        name = "jsonPoint",
                        datatype = "String",
                        parameterType = "Derived",
                        direction = "Output")
        return [arcpy_point, json_point]

    def isLicensed(self):
        """Set whether tool is licensed to execute."""
        return True

    def updateParameters(self, parameters):
        """Modify the values and properties of parameters before internal
        validation is performed.  This method is called whenever a parameter
        has been changed."""

    def updateMessages(self, parameters):
        """Modify the messages created by internal validation for each tool
        parameter.  This method is called after internal validation."""

    def execute(self, parameters, messages):
        """Run the tool"""

        # setting parameter[0] to a Point doesn't do anything.  
        # The type ends up being None in the message (?)
        point = arcpy.Point(-111, 42)
        parameters[0].value = point 

        # json point succeeds cause its String
        ptGeom = arcpy.PointGeometry(point)
        parameters[1].value = ptGeom.JSON 
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1 Reply
Occasional Contributor

Circumstances are slightly different, I ran into this issue when trying to set defaults in updateParameters. But I imagine the solution is the same and since this has been around since 2013 and nobody has replied I thought I would!

I'm using ArcGIS Pro and tested your script and it appeared to work

Try setting it as a string like so

s_val = "{0} {1}".format(point.X, point.Y)
parameter.value = s_val‍‍‍‍

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