Error When Running Calculate Value

cwh

Hello Everyone,

I have a model which runs the calculate value tool:

The code in the tool is:

When the model runs the following errors are displayed:

I'm not sure what the errors are related to. What's strange is that the code does seem to execute: it displays the extent of the site_polygon layer, sets the scale to 1:4000, then creates the JPG file.

Any insights appreciated. Thanks!

cwh

I thought I would post the final script that created the expected results in the jpg file:

def main():
    import arcpy
    # will overwrite existing jpg
    arcpy.env.overwriteOutput = True

    # read the parameter from the tool
    loc_no = arcpy.GetParameterAsText(0)

    # define the path of the mxd
    mxd_file = r'H:\chris\{0}\{0} - actual_use.mxd'.format(loc_no)
    jpg_file = r'H:\chris\{0}\{0}-actual_use.jpg'.format(loc_no)
    if arcpy.Exists(mxd_file):
        arcpy.AddMessage("Using MXD {0}".format(mxd_file))
        try:
            mxd = arcpy.mapping.MapDocument(mxd_file)
            df = arcpy.mapping.ListDataFrames(mxd)[0]
            arcpy.AddMessage("DF extent on startup is: {0}".format(df.extent))
            arcpy.AddMessage("DF scale on startup is: {0}".format(df.scale))
            lyr = arcpy.mapping.ListLayers(mxd, 'site_polygon', df)[0]
            ext = lyr.getExtent()
            arcpy.AddMessage("extent of lyr: {0}".format(ext))
            new_extent = df.extent
            new_extent.XMin, new_extent.YMin = ext.XMin, ext.YMin
            new_extent.XMax, new_extent.YMax = ext.XMax, ext.YMax
            arcpy.AddMessage("extent of new_extent: {0}".format(new_extent))
            df.extent = new_extent
            df.scale = 4000
            arcpy.AddMessage("DF extent after assignment is: {0}".format(df.extent))
            arcpy.AddMessage("DF scale after assignment is: {0}".format(df.scale))
            arcpy.AddMessage("Exporting to JPEG: {0}".format(jpg_file))
            arcpy.mapping.ExportToJPEG(mxd, jpg_file)
            del mxd
        except Exception as e:
            arcpy.AddError("Error: {0}".format(e))
    else:
        arcpy.AddWarning("MXD {0} not found!".format(mxd_file))

if __name__ == '__main__':
    main()

Something interesting is that while the image exported is what I'm expecting:

Nothing ever changed in the map window from when the mxd opened. I always expected that the extent would change in the map window and then the image would be created based on that: