arcPy Jason Tipton @jTiptonGIS [email protected] 

Add To Path Env Variable • Open cmd • setx path "%path%; C:\Python27\ArcGISx6410.1“ • open new cmd. "echo %path%" to confirm OR • Right Click Computer > Properties > Advanced System Settings > Environment Variables • Open Path and add path to Python 

Why Arcpy over Model Builder • Greater control over processes • More reliable results • Faster • Can be run outside of ArcMap – import arcpy 

Today’s Topics • MXD tweaks (Fix Broken Sources) • ArcPy prevails when Model Builder Fails • Cursors, Messages, inputs, Selections • Use Case (Auto-clipper) • GUI’s (Tkinter) 

MXD - Update Source • What happens when drives/directories change locations? • mxd = arcpy.mapping.MapDocument(fullpath) • mxd.findAndReplaceWorkspacePaths(dirIn,dir Out,False) 

MXD – List Broken Sources • mxd = arcpy.mapping.MapDocument(‘mxdPath') • arcpy.mapping.ListBrokenDataSources(mxd) 

MXD • View Example 

Input Paramaters 0 1 2 3 arcpy.GetParameterAsText(0) arcpy.GetParameterAsText(1) arcpy.GetParameterAsText(2) arcpy.GetParameterAsText(3) 

Messaging • Arcpy.AddMessage(“message”) • Arcpy.AddWarning(“message”) • Arcpy.AddError(“message”) Message Warning 

Cursors • Arcpy.SearchCursor(“layer”,{where}) – Used to read through each row in feature class • Arcpy.UpdateCursor(“layer”, {where}) – Same, but with the ability to edit/delete – Call cursorObject.updateRow(rowObject) to commit • Arcpy.InsertCursor(“layer”) • Insert data 

Cursor Structure cursor = arcpy.UpdateCursor(“layer”, {where}) for row in cursor: # loop through each row x = row.FieldName x = row.getValue(“FieldName”) row.FieldName2 = y row.setValue(“FieldName2”, y) cursor.updateRow(row) 

Water Well Example • Cursors • Messages • Inputs • Selections – Select by Attribute – Select by Location • Where to get help on syntax 

ArcPy When MB Fails • Address Locator Example • Not that complicated, but MB fails • Must run model halfway once, then run again for it to work. • Python works 1st time every time. . . • View Example 

Use Case – Raster Clipper • Automatically detects new tiffs • Determines if they have been georeferenced • Clip them to the best Quad boundary • View Example 

Useful Tools/Links • Pywin IDE • Python for Visual Studio • Notepad ++ 

Python 64 Bit • Be cautious. Things will break! • External libraries may not be compiled • Use Python for VS to run in 32 bit 

Questions?