topic Re: Merge_management and fieldmappings problem in Python Questions

Merge_management and fieldmappings problem

ChrisMatthews — Wed, 17 Feb 2016 16:06:28 GMT

I am using arcpy.Merge_management to combine 4 CSV files into SDE. I attempting to use fieldmappings to rename the field headers, and this is causing it to crash. I've not used fieldmapping with more than two datasets simaltaneously before...

The error is trapped by the try loop, but is returning no information. Any help would be appreciated.

try:

if booContinue == True:

fieldmappings = arcpy.FieldMappings()

fieldmap1 = arcpy.FieldMap()

fieldmappings.addTable(rg_Layer)

fieldmappings.addTable(ox_Layer)

fieldmappings.addTable(sn_Layer)

fieldmappings.addTable(sp_Layer)

fieldmap1.addInputField(rg_Layer,"field1")

fieldmap1.addInputField(ox_Layer,"field1")

fieldmap1.addInputField(sn_Layer,"field1")

fieldmap1.addInputField(sp_Layer,"field1")

fieldout1 = fieldmap1.outputField

fieldout1.name = "PCODE"

fieldmap1.outputField = fieldout1

fieldmappings.addFieldMap(fieldmap1)

arcpy.Merge_management([rg_Layer,ox_Layer,sn_Layer,sp_Layer], pc_layer, fieldMappings)

msg = msg + "\n" + outname + " created"

except:

msg = msg + "\n" + "error creating " + outname + " - " + "\n" + arcpy.GetMessages(2)

booContinue = False

Re: Merge_management and fieldmappings problem

DanPatterson_Retired — Wed, 17 Feb 2016 18:43:39 GMT

Chris does fieldmapping work manually with csv files? The help files only makes reference to featureclasses/shapefiles in the help topic but doesn't indicate what it can be used for

FieldMappings—Help | ArcGIS for Desktop

Re: Merge_management and fieldmappings problem

XanderBakker — Thu, 18 Feb 2016 00:49:38 GMT

Wouldn't it be easier to use a csv reader and order fields (indexes to fields) manually. Just seems that using FieldMappings (if it works on CSV files as Dan mentions) makes it unnecessarily complex.

Re: Merge_management and fieldmappings problem

ChrisMatthews — Mon, 22 Feb 2016 10:42:37 GMT

It is ironic that it ends up more complex using Field_Mapping, I wanted to use it to keep things simply.

Re: Merge_management and fieldmappings problem

ChrisMatthews — Mon, 22 Feb 2016 10:44:41 GMT

I've managed to get the Field_Mapping working, but as a massively complex (hard to read) parameter to the Merge_management tool - see below, so it does seem that it is possible to use field mapping with CSVs.

arcpy.Merge_management("rg_Layer;ox_Layer;sn_Layer;sp_Layer", GISLive_GISADMIN_AA_TEST_70, "Postcode \"Postcode\" true true false 255 Text 0 0 ,First,#,rg_Layer,Field1,-1,-1,ox_Layer,Field1,-1,-1,sn_Layer,Field1,-1,-1,sp_Layer,Field1,-1,-1;Quality \"Quality\" true true false 4 Long 0 0 ,First,#,rg_Layer,Field2,-1,-1,ox_Layer,Field2,-1,-1,sn_Layer,Field2,-1,-1,sp_Layer,Field2,-1,-1;POBox \"POBox\" true true false 255 Text 0 0 ,First,#,rg_Layer,Field3,-1,-1,ox_Layer,Field3,-1,-1,sn_Layer,Field3,-1,-1,sp_Layer,Field3,-1,-1;TotalDPS \"TotalDPS\" true true false 4 Long 0 0 ,First,#,rg_Layer,Field4,-1,-1,ox_Layer,Field4,-1,-1,sn_Layer,Field4,-1,-1,sp_Layer,Field4,-1,-1;ResDPS \"ResDPS\" true true false 4 Long 0 0 ,First,#,rg_Layer,Field6,-1,-1,ox_Layer,Field6,-1,-1,sn_Layer,Field6,-1,-1,sp_Layer,Field6,-1,-1;ComDPS \"ComDPS\" true true false 4 Long 0 0 ,First,#,rg_Layer,Field7,-1,-1,ox_Layer,Field7,-1,-1,sn_Layer,Field7,-1,-1,sp_Layer,Field7,-1,-1;POBoxDPS \"POBoxDPS\" true true false 4 Long 0 0 ,First,#,rg_Layer,Field8,-1,-1,ox_Layer,Field8,-1,-1,sn_Layer,Field8,-1,-1,sp_Layer,Field8,-1,-1;Matched \"Matched\" true true false 4 Long 0 0 ,First,#,rg_Layer,Field9,-1,-1,ox_Layer,Field9,-1,-1,sn_Layer,Field9,-1,-1,sp_Layer,Field9,-1,-1;Unmatched \"Unmatched\" true true false 4 Long 0 0 ,First,#,rg_Layer,Field10,-1,-1,ox_Layer,Field10,-1,-1,sn_Layer,Field10,-1,-1,sp_Layer,Field10,-1,-1;XCoord \"XCoord\" true true false 4 Long 0 0 ,First,#,rg_Layer,Field11,-1,-1,ox_Layer,Field11,-1,-1,sn_Layer,Field11,-1,-1,sp_Layer,Field11,-1,-1;YCoord \"YCoord\" true true false 4 Long 0 0 ,First,#,rg_Layer,Field12,-1,-1,ox_Layer,Field12,-1,-1,sn_Layer,Field12,-1,-1,sp_Layer,Field12,-1,-1;PCType \"PCType\" true true false 255 Text 0 0 ,First,#,rg_Layer,Field19,-1,-1,ox_Layer,Field19,-1,-1,sn_Layer,Field19,-1,-1,sp_Layer,Field19,-1,-1")