topic Re: Problem with 'Dissolve' and Field statistic in Python Questions

Problem with 'Dissolve' and Field statistic

GabrielBacca-Cortes — Thu, 15 Jan 2015 20:57:26 GMT

Hi All - I am trying to use dissolve_management applying it to obtain a field statistic {MAX} from the field [TIME]. The format of the field 'Time' is numeric (float). I am doing this for a set of FCs running through a For-loop. When I remove the field statistic option/constraint from the code it runs perfectly, but I need that Time statistic, as well as other statistics from other fields, but I figured if I get it for one I could get them for the others later.

The code gets stuck on the first FC of the loop. Thanks much for any insight on this !!

# Import system modules

import arcpy, os

from arcpy import env

# Set environment settings

env.workspace = r"C:\GIS\Track1\1_Orig\T_shp\shp"

# Set local variables

folder = r"C:\GIS\Track1\1_Orig\T_dis"

dissolveFields = ""

wildcard = ""

fctype = ""

try:

infcs = arcpy.ListFeatureClasses(wildcard, fctype)

print infcs

for fc in infcs:

outfcs = folder + os.sep + fc

print outfcs

#outfcs = os.path.join(folder, fc)

arcpy.Dissolve_management (fc, outfcs, dissolveFields, ["TIME",{MAX}],

"SINGLE_PART","DISSOLVE_LINES")

except:

print arcpy.GetMessages(2)

Cheers,

Gabriel

Re: Problem with 'Dissolve' and Field statistic

RussellHooper — Thu, 15 Jan 2015 21:26:41 GMT

Hi Gabriel,

I think the MAX in your Dissolve tool should be in quotes.

What error message did you get?

Russell

Re: Problem with 'Dissolve' and Field statistic

GabrielBacca-Cortes — Thu, 15 Jan 2015 21:44:00 GMT

Hi Russell - thanks for your response. I tried both 'MAX' and "MAX" and didn't work, when I removed { }, I get an error saying that the Statistical method is empty.

I don't get any errors, I am just not getting any results. The 'print outfcs' helps me visualize by only printing the first output FC that the loop is stalled. When I remove the field statistics option, I get the entire list of output FCs, showing that the loop went through successfully. Otherwise no error, only at the bottom bar of the PythonWin a message saying that the Script 'returned exit code 0'.

Any ideas? thanks

Gabriel

Re: Problem with 'Dissolve' and Field statistic

FilipKrál — Thu, 15 Jan 2015 22:09:47 GMT

Hi, try this:

arcpy.Dissolve_management(fc, outfcs, dissolveFields, [["TIME","MAX"]], "SINGLE_PART","DISSOLVE_LINES")

The curly brackets in the documentation mean that the parameter is optional.

[[field, {statistic_type}],...] means that you can supply a list lists and of strings (although that's not obvious). The first item of the list is the field name as string, the second item is and optional string specifying the statistic.

Hope this will work.

Filip.

Re: Problem with 'Dissolve' and Field statistic

GabrielBacca-Cortes — Fri, 16 Jan 2015 14:37:55 GMT

Thanks Filip !

It worked.

Regards,

Gabriel