topic Re: Search and Update Cursors in Python Questions

Search and Update Cursors

ionarawilson1 — Wed, 09 Oct 2013 19:40:31 GMT

I need to use search and update cursors to get the values from one feature class to another. Before this code worked because I had only one record to be updated, but now I may have more than one. How can I change it to let it update many records? Thanks

    countycode = tuple(arcpy.da.SearchCursor("Countieslayer", "FIPS_TXT"))[0][0]     urows = arcpy.da.UpdateCursor("Stewardship", "County")     for urow in urows:         urow[0] = countycode         urows.updateRow(urow)

Re: Search and Update Cursors

ionarawilson1 — Thu, 10 Oct 2013 13:47:43 GMT

This worked, I just had to create temporary layers, instead of feature classes

# Create new field mappings and addd both feature classes  fieldmappings = arcpy.FieldMappings() fieldmappings.addTable(Input_Polygons) fieldmappings.addTable(Counties)  # create output feature for spatial join outstewardshipcounties = os.path.join(arcpy.env.scratchGDB, "StewardshipCounties")  #run spatial joint tool  arcpy.SpatialJoin_analysis(Input_Polygons, Counties, outstewardshipcounties , "#", "#", fieldmappings, "HAVE_THEIR_CENTER_IN")  #create dictionary  path_dict = { } rows = arcpy.SearchCursor(outstewardshipcounties) for row in rows:     keyrow = row.getValue("ObjectID")     valrow = row.getValue("FIPS_TXT")     path_dict[keyrow] = valrow  urows = arcpy.UpdateCursor(Input_Polygons) for urow in urows:     upkey = urow.getValue("ObjectID")     if upkey in path_dict:         urow.setValue("County", path_dict[upkey])         urows.updateRow(urow) del row, rows, urow, urows

Re: Search and Update Cursors

AliciaMein — Thu, 10 Oct 2013 17:01:20 GMT

I have a use for the update and search cursors.
first question: why are you using the os.path in your script instead of the addjoin management function?
Alicia

Re: Search and Update Cursors

ionarawilson1 — Thu, 10 Oct 2013 17:06:02 GMT

Add join is to join layers and the os.path.join is just adding the strings to create a layer in that scratch workspace

Re: Search and Update Cursors

AliciaMein — Thu, 10 Oct 2013 18:45:56 GMT

I understand the Arcpy module and navigate the help at esri well but is there documentation on the os module?
I will post a new thread for my update and search cursor issue and look forward to seeing a reply from you.
Thanks,
Alicia

Re: Search and Update Cursors

ionarawilson1 — Thu, 10 Oct 2013 19:06:03 GMT

Here is some info that should help you:

http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//004000000008000000.htm