Projecting single pointGeometry object with ArcPy?

Question

In an attempt to create a python add-in for ArcMap that will pass x and y coordinates to another application via a mouse click on the map, I have written the following code. I need the output coordinates to be in WGS_1984 and therefore have to project a geometry object. The problem I'm running into is that whenever the script executes the projectAs() method I get the following error. Code at bottom

enter image description here

import arcpy
import pythonaddins
import webbrowser
import os, sys
from arcpy import env
arcpy.env.overwriteOutput = True
class ToolClass2(object):
 """Implementation for StreetView_addin.tool (Tool)"""
 def __init__(self):
 self.enabled = True
 self.shape = "NONE" # Can set to "Line", "Circle" or "Rectangle" for interactive shape drawing and to activate the onLine/Polygon/Circle event sinks.
 def onMouseDownMap(self, x, y, button, shift):
 mxd = arcpy.mapping.MapDocument("CURRENT")
 df = arcpy.mapping.ListDataFrames(mxd)[0]
 sr_df = df.spatialReference
 xValue = x
 yValue = y
 pointList = [[xValue, yValue]]
 point = arcpy.Point()
 for pt in pointList:
 point.X = pt[0]
 point.Y = pt[1]
 pointGeometry = arcpy.PointGeometry(point, sr_df)
 pointGeometry.projectAs("WGS 1984")
 centroid = str(pointGeometry.centroid)
 centList = centroid.split(" ")
 xValue2 = centList[0]
 yValue2 = centList[1]

I have tried adding the optional transformation for the projectAs() method as well without success. What am I missing here?

• Michael Stimson: The problem would appear to be that the point has no spatial reference to start from try pointGeometry=arcpy.PointGeometry(point,df.spatialReference) before .projectAs. The rest of the code looks fine but doesn't appear to do much, I assume you're exporting xValue2 and yValue2 to a file or using them in some other way..
• GeoJohn: @Michael Miles-Stimson The sr_def object contains the original spatial ref via the 3rd and 4th lines. You have assumed correctly, this is only a portion of what I'm doing, xValue2 and yValue2, are going to be used by another portion of the script once I can get them right. I suppose another way to ask the same thing would be... How do I make the centroid property return the Decimal Degree equivalent in "WGS 1984"?
• Michael Stimson: Your code is mostly right but you're destroying the spatial reference by taking it out to a string and replacing underscores, supply the spatial reference as an object derived from the data frame.
• GeoJohn: That makes sense, and it now works except when I try to return the centroid it is still the original x, and y values. I'll update the code to show where it's at now. Thanks
• mkennedy: What's the data frame's / input coordinate system?

Answer 1

@GeoJohn: I don't know if you've solved this, but the result of the pointGeometry.projectAs("WGS 1984") needs to be assigned to a result variable (e.g., projectedPointGeometry = pointGeometry.projectAs("WGS 1984")). The original pointGeometry is unchanged by the projectAs method. The result variable should have the location in decimal degrees. I need to do a similar thing, and was able to figure it out based on your code, so thank you for posting this question.

• GeoJohn: Wow! No, I never solved this. What a simple oversight. I sort of gave up on this project since it was just something I was trying to implement for my own use. Thanks for your answer! I can probably finish this now!
• jbchurchill: The code helped me as well!

Answer 2

for transforming form Swiss-LV95 to WGS84 I currently use

arcpy.PointGeometry(arcpy.Point(swissX,swissY),arcpy.SpatialReference(2056)).projectAs(arcpy.SpatialReference(4326))

with ArcGIS 10.1