topic Re: Calculate Field from Feature Class Name in Python Questions

Calculate Field from Feature Class Name

Kklitt — Wed, 17 Jan 2024 17:46:11 GMT

Hello, I'm a python newbie seeking help.

I'm attempting to create a python script that iterates through a file geodatabase with feature classes and feature classes within feature datasets to calculate the field 'NRHP_Type' with the name of the feature class.

For example, all points in the feature class crothr_pt would have 'Other' written in the NRHP_Type field.

This is what I have so far:

import arcpy import arcgis import os import sys def listFcsInGDB(gdb): #list all Feature Classes in a geodatabase, including inside Feature Datasets ''' arcpy.env.workspace = gdb print('Processing ', arcpy.env.workspace) fcs = [] for fds in arcpy.ListDatasets('','feature') + ['']: for fc in arcpy.ListFeatureClasses('','',fds): #yield os.path.join(fds, fc) fcs.append(os.path.join(fds, fc)) return fcs codeblock = """ def getNRHPType(nrhpfc): if nrhpfc in ['crothr_ln','crothr_pt','crothr_py']: return 'Other' elif nrhpfc in ['crbldg_pt','crbldg_py']: return 'Building' elif nrhpfc in ['crobj_ln','crobj_pt','crobj_py']: return 'Object' elif nrhpfc in ['crsite_ln','crsite_pt','crsite_py']: return 'Site' elif nrhpfc in ['crstru_ln','crstru_pt','crstru_py']: return 'Structure' elif nrhpfc in ['crsurv_ln','crsurv_py','crsurv_pt']: return 'Survey' elif nrhpfc in ['crdist_py']: return 'District' else: return 'undefined NRHP type'""" gdb = arcpy.GetParameterAsText(0) fcsLi = listFcsInGDB(gdb) for fc in fcsLi: inField = "NRHP_Type" expression = getNRHPType(os.path.basename(fc)) arcpy.CalculateField_management(fc, inField, ""+expression+"", "PYTHON", codeblock) print(fc+" completed")

The error message:

Traceback (most recent call last):
File "C:\junk.tbx#CreateNRHPField1_NewToolbox.py", line 41, in <module>
NameError: name 'getNRHPType' is not defined

Here are the guides I've been using:

arcgis desktop - Adding file name to attribute field using Calculate Field? - Geographic Information Systems Stack Exchange

arcpy - Listing all feature classes in File Geodatabase, including within feature datasets? - Geographic Information Systems Stack Exchange

Thank you!

Re: Calculate Field from Feature Class Name

DavidPike — Wed, 17 Jan 2024 20:51:10 GMT

have not looked that the rest of your code or code logic is correct, but at a glance possibly:

for fc in fcsLi: inField = "NRHP_Type" expression = "getNRHPType(os.path.basename(fc))" arcpy.CalculateField_management(fc, inField, "'"+expression+"'", "PYTHON", codeblock) print(fc+" completed")

Re: Calculate Field from Feature Class Name

RhettZufelt — Wed, 17 Jan 2024 21:31:51 GMT

the message says the function getNRHPType is not defined. Probably because it is seeing it inside the """ of the code block and thinks it is comment.

Try removing the codeblock = """ and the matching """, should at least make that error go away.

Re: Calculate Field from Feature Class Name

Kklitt — Wed, 17 Jan 2024 21:41:47 GMT

Hi @DavidPike ,

The code ran without error, but it didn't accomplish what I was hoping it would do. It now writes: "getNRHPType(os.path.basename(fc))" to the field.

Re: Calculate Field from Feature Class Name

Kklitt — Wed, 17 Jan 2024 21:54:44 GMT

After working through it, I realized that I could accomplish this task without a calculate field code block. Here's what I came up with!

import arcpy import arcgis import os import sys def listFcsInGDB(gdb): ''' list all Feature Classes in a geodatabase, including inside Feature Datasets ''' arcpy.env.workspace = gdb print('Processing ', arcpy.env.workspace) fcs = [] for fds in arcpy.ListDatasets('','feature') + ['']: for fc in arcpy.ListFeatureClasses('','',fds): #yield os.path.join(fds, fc) fcs.append(os.path.join(fds, fc)) return fcs gdb = arcpy.GetParameterAsText(0) fcsLi = listFcsInGDB(gdb) for fc in fcsLi: inField = 'NRHP_Type' fileName = os.path.basename(fc) if fileName in ['crothr_ln','crothr_pt','crothr_py']: fieldInput = 'Other' elif fileName in ['crbldg_pt','crbldg_py']: fieldInput = 'Building' elif fileName in ['crobj_ln','crobj_pt','crobj_py']: fieldInput = 'Object' elif fileName in ['crsite_ln','crsite_pt','crsite_py']: fieldInput = 'Site' elif fileName in ['crstru_ln','crstru_pt','crstru_py']: fieldInput = 'Structure' elif fileName in ['crsurv_ln','crsurv_py','crsurv_pt']: fieldInput = 'Survey' elif fileName in ['crdist_py']: fieldInput = 'District' else: fieldInput = 'undefined NRHP type' arcpy.CalculateField_management(fc, inField, "'"+fieldInput+"'", "PYTHON3") print(fc+" completed")

Might not be the prettiest but it got the job done. Thank you @DavidPike and @RhettZufelt !