1. GEOG 375 Final Project
Robert Abbotts
Spring 2013

2. Code Explanation Set Input shapefile from user input
inFeatures = arcpy.GetParameterAsText(0)
Set local variable to required shapefiles
join_features = "//sac/GIS_Script_Shapefiles/24kquad_trim.shp"
plss="//sac/GIS_Script_Shapefiles/pls_fill.shp"
county="//sac/GIS_Script_Shapefiles/Counties.shp"
Get input folder
inputfolder = os.path.dirname(inFeatures)
Check if shapefiles exist, if they are, delete them
if os.path.isfile(inputfolder+"\out.shp"):
arcpy.Delete_management(inputfolder+"\out.shp")
if os.path.isfile(inputfolder+"\outcounty.shp"):
arcpy.Delete_management(inputfolder+"\outcounty.shp")
if os.path.isfile(inputfolder+"\PExport.shp"):
arcpy.Delete_management(inputfolder+"\PExport.shp")
Set local variables for shapefiles
out_feature_class = inputfolder+"\out.shp"
out_county_class = inputfolder+"\outcounty.shp"
outFeatures = inputfolder+"\PExport.shp"

3. Code Explanation
Use Spatial join geoprocessing tools to create output shapefiles
arcpy.SpatialJoin_analysis(inFeatures, join_features, out_feature_class)
arcpy.SpatialJoin_analysis(out_feature_class, plss,out_county_class)
arcpy.SpatialJoin_analysis(out_county_class, county, outFeatures)

4. Code Explanation Set local variables for table fields
fieldName1 = "GIS_ID"
fieldLength = 16
fieldName2 = "DDLAT"
fieldPrecision2 = 9
fieldName3 = "DDLON"
fieldPrecision3 = 9
fieldName4 = "TEALE_X"
fieldPrecision4 = 9
fieldName5 = "TEALE_Y"
fieldPrecision5 = 9

5. Code Explanation Add GIS_ID, DDLAT, DDLON, TEALE_X, TEALE_Y fields
arcpy.AddField_management(outFeatures, fieldName1, "TEXT", "", "", fieldLength)
Calculate fields for update data to dispplay date, GPS date and GPS person in the table
arcpy.CalculateField_management(outFeatures, fieldName1,
'"%s%s%s%s" % (!Datafile![0:8], !GPS_Date![-4:-1],!GPS_Date![-1], !GPS_Person!)',
"PYTHON")
arcpy.AddField_management(outFeatures, fieldName2, "DOUBLE", "", "","","","NULLABLE","")
arcpy.AddField_management(outFeatures, fieldName3, "DOUBLE", "", "","","","NULLABLE","")
arcpy.AddField_management(outFeatures, fieldName4, "DOUBLE", "", "","","","NULLABLE","")
arcpy.AddField_management(outFeatures, fieldName5, "DOUBLE", "", "","","","NULLABLE","")
Add X Y fields and calculate fields for X, Y from Point_X and Point_Y
arcpy.AddXY_management(outFeatures)
arcpy.CalculateField_management(outFeatures, fieldName4,
'!POINT_X!', "PYTHON")
arcpy.CalculateField_management(outFeatures, fieldName5,
'!POINT_Y!', "PYTHON")

6. Code Explanation
Convert X Y to Lat/Lon using update cursor using for loop
desc = arcpy.Describe(outFeatures)
shapefieldname = desc.ShapeFieldName
try:
row, rows = None, None
rows = arcpy.UpdateCursor(outFeatures, r'', \
r'GEOGCS["GCS_WGS_1984",' + \
'DATUM["D_WGS_1984",' + \
'SPHEROID["WGS_1984", , ]],' + \
'PRIMEM["Greenwich",0],' + \
'UNIT["Degree", ]]')
for row in rows:
feat = row.getValue(shapefieldname)
pnt = feat.getPart()
row.DDLat = pnt.Y
row.DDLon = pnt.X
rows.updateRow(row)

7. Code Explanation
Except clause if error occurred and delete table rows and temp shapefiles
except:
if not arcpy.GetMessages() == "":
arcpy.AddMessage(arcpy.GetMessages(2))
finally:
# Regardless of whether the script succeeds or not, delete
# the row and cursor #
if row:
del row
if rows:
del rows
Delete fields and shapefile
dropFields = ["POINT_X", "POINT_Y", "Join_Count", "TARGET_FID","Join_Cou_1","TARGET_F_1","Join_Cou_2","TARGET_F_2","AREA","PERIMETER", "DRGINDEX_","DRGINDEX_I", "OCODE", "USGS100","USGS250","CD","AREA_1","PERIMETE_1","PLSFILL_","PLSFILL_ID","X_COORD","Y_COORD","AREA_12","PERIMETE_2","COUNTY_","COUNTY_ID","Range_1","Staff"]
arcpy.DeleteField_management(outFeatures, dropFields)
arcpy.Delete_management(inputfolder+"\out.shp")
arcpy.Delete_management(inputfolder+"\outcounty.shp")
Get the map document mxd
mxd = arcpy.mapping.MapDocument("CURRENT")
Get the data frame
df = arcpy.mapping.ListDataFrames(mxd,"*")[0]
Create a new layer
newlayer = arcpy.mapping.Layer(outFeatures)
Add the layer to the map at the bottom of the TOC in data frame 0
arcpy.mapping.AddLayer(df, newlayer,"TOP")
Refresh arcmap view, table of content
arcpy.RefreshActiveView()
arcpy.RefreshTOC()
del mxd, df, newlayer

8. Output outFeatures is PExport.shp
If Arcmap is open when the script is run using ArcToolbar, a temp new layer (outFeatures) will be displayed on top of table of content in ArcMap.

9. Summary
First, the python script is to get user input shapefile from arctoolbox prompt.
Second, the input shapefiles join other required shapefiles to create result output shapefile.
Third, check if empty or none data fields exist in table using searchcursor function.
Fourth, using add fields (add GIS_ID, DDLAT, DDLON, TEALE_X, TEALE_Y fields and calculate fields to populate the table fields with updated data using updatecursor function.
Then, delete temporary shapefiles and table rows.
Finally, add a new layer (outFeatures shapefile) to ArcMap on top of the table of content. And refresh the ArcMap document.