Batch merging field mapping

Question

I made the following script to merge shape files of different format types (poly,line, points):

def main(): 
 import arcpy
 from arcpy import env
 import globalpath
 import os
 env.workspace = globalpath.toolDataPath
 dataPath=globalpath.toolDataPath
 arcpy.env.overwriteOutput = True
 #try:
 DataTypeL=[("Polygon","mergedTOTPoly.shp"),("Polyline","mergedTOTLines.shp"),("Point","MergedTOTPoint.shp")]
 for dType in DataTypeL:
 (Typei,Title)=dType
 matches = []
 counter=0
 for dirpath, dirnames, filenames in arcpy.da.Walk(dataPath+"\\UtilityDataFromZorgel",datatype="FeatureClass",type=Typei):
 for filename in filenames: 
 match = ( os.path.join(dirpath, filename))
 arcpy.AddMessage(m)
 matches.append (match)
 counter = counter + 1 
 arcpy.Merge_management(matches, dataPath+"\\utilities"+Title)
 arcpy.AddMessage(str(counter)+" "+str(Typei)+" layers were merged into "+ str(filename))
 #except:
 arcpy.AddWarning("Merging Utility Layers Failed")
if __name__ == "__main__":
 main()

I get the following error:

Traceback (most recent call last):
 File "C:\merger.py", line 30, in <module>
 main()
 File "C:\merger.py", line 25, in main
 arcpy.Merge_management(matches, dataPath+"\\utilities"+Title)
 File "c:\program files (x86)\arcgis\desktop10.1\arcpy\arcpy\management.py", line 3762, in Merge
 raise e
ExecuteError: ERROR 001156: Failed on input OID 0, could not write value 'Kanata' to output field TILE_ID
Failed to execute (Merge).

When I merge these files manually from arcmap it works, and fields are mapped as follows:

"STRUCT_TYP \"STRUCT_TYP\" true true false 18 Text 0 0 ,First,#,Allstream_hdwr_L,STRUCT_TYP,-1,-1,allstream_L,STRUCT_TYP,-1,-1,Allstream_lines_L,STRUCT_TYP,-1,-1,Allstream_text_L,STRUCT_TYP,-1,-1,Atria_lines_L,STRUCT_TYP,-1,-1,Atria_text_L,STRUCT_TYP,-1,-1,bell_L,STRUCT_TYP,-1,-1)

where STRUCT_TYP is a shared field.

please let me know how can I get around this error, and if it is indeed mapping the fields how can I do it in batched merging, or should I merge each file individually?

• Farid Cheraghi: Take a deep look into this online topic: Mapping input fields to output fields

Answer 1

I got it to run on a directory full of parcels, PLSS, and annexations. The directory had a mix of shapefiles and file geodatabases. I defined the datapath differently, but otherwise changed nothing.

It failed on the 13th polygon feature class. The resulting shapefile had 62 fields and 44525 records. My failure was a type mismatch, so it was different than yours.

Try running on a subset of your input feature classes and add some print commands to tell you which feature class failed. You may have a field name or file name that is invalid in arcpy, but works when the feature class is inserted as a layer in ArcMap.

• Solaire: I'll try that and post what I find
• Solaire: and why did you get a type mismatch at that point I'm curious
• Solaire: adding error handlers shows that only polygons are giving me errors, i removed some of the shape files to see if the issue persists it appears that "TILE_ID" is a problematic field as the problem appears with different values other than "Kanata"
• jlcrawf0: Is the "TILE_ID" field the same length (in characters) in all of your source files? If not, then rename one of your files with a wider "TILE_ID" field so that it is processed first.
• Solaire: no it's not the same length, I could have swore its about text length, i was trying to recalculate the value for "TILE_ID" as str(!TILE_ID!)[:4]