topic Removing characters from a Feature Class file name in Python Questions

Removing characters from a Feature Class file name

MichaelTomiak — Sun, 14 Feb 2021 21:35:33 GMT

This should be a simple answer ... I'm trying to just remove the first 25 characters from a list (>90 in number) of Feature classes (raster datasets) within a .gdb.

All the file names are named the same except for the last 9 digits (hence why I am trying to remove the first 25).
I would then like to add some standard text to all the FCs (in the example "Hello")

My attempt from other threads comprises the following (but has not worked so far):

-------------------

import arcpy
import os

dir = r'C:\Users\X\Desktop\X\X.gdb'

arcpy.env.workspace = dir

for ras in arcpy.ListRasters ("*"):
print (ras) #original raster name
basename = ras.split("*")[:25] #strips the first 25 characters from original raster name
newrastername = "Hello" + basename
print (newrastername)
arcpy.CopyRaster_management(ras, newrastername) #create a new raster with the new/updated name

----------------------

Error received:

---------------------------------------------------------------------------
SyntaxError                               Traceback (most recent call last)
File C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\ast.py, in parse:
Line 35:    return compile(source, filename, mode, PyCF_ONLY_AST)

SyntaxError: Missing parentheses in call to 'print'. Did you mean print(ras #original raster name)? (<string>, line 😎

Re: Removing characters from a Feature Class file name

DavidPike — Sun, 14 Feb 2021 21:31:07 GMT

Can you share your print statement returns and your error messages? It looks ok, but what is ras.split("*") for?

Re: Removing characters from a Feature Class file name

MichaelTomiak — Sun, 14 Feb 2021 21:36:53 GMT

yes apologies

It is to try to remove the first 25 (took the split from some research on line, but likely not the most sensible function to use)

Re: Removing characters from a Feature Class file name

DanPatterson — Sun, 14 Feb 2021 21:54:59 GMT

split produces pieces, you have to determine which one first then slice off the characters. For example

ras = "left*right" ras.split("*")[0][:2] 'le' ras.split("*")[1][:2] 'ri' ras.split("*")[0][-2:] 'ft' ras.split("*")[1][-2:] 'ht'

or skip the split

ras[-5:] 'right' ras[:5] 'left*'

Re: Removing characters from a Feature Class file name

DavidPike — Sun, 14 Feb 2021 22:03:17 GMT

well that's not quite right. Just use

basename = ras[:25]

and forget about the .split("*") unless you want to create a list of strings split at an asterisk *. in that case use

basename = ras.split("*")[0][:25]

Edit - I also think you need [25:] not [:25]

Re: Removing characters from a Feature Class file name

MichaelTomiak — Sun, 14 Feb 2021 22:37:24 GMT

thank you. However I'm still getting an 'indentation' error:

IndentationError                          Traceback (most recent call last)
File C:\Program Files\ArcGIS\Pro\bin\Python\envs\arcgispro-py3\Lib\ast.py, in parse:
Line 35:    return compile(source, filename, mode, PyCF_ONLY_AST)

IndentationError: expected an indented block (<string>, line 10)

Original code:

import arcpy
import os

dir = r'C:\Users\Michael.Tomiak\Desktop\25\Copy.gdb'

arcpy.env.workspace = dir

for ras in arcpy.ListRasters ("*"):
print (ras)
basename = ras[25:] #strips the first 25 characters from original raster name
newrastername = basename
print (newrastername)
arcpy.CopyRaster_management(ras, newrastername) #create a new raster with the new/updated name

Re: Removing characters from a Feature Class file name

DavidPike — Sun, 14 Feb 2021 22:44:22 GMT

import arcpy import os dir = r'C:\Users\X\Desktop\X\X.gdb' arcpy.env.workspace = dir for ras in arcpy.ListRasters ("*"): #print (ras) #original raster name #print(ras.split("*")) basename = ras[25:] #strips the first 25 characters from original raster name newrastername = "Hello" + basename print (newrastername) arcpy.CopyRaster_management(ras, newrastername) #create a new raster with the new/updated name

Re: Removing characters from a Feature Class file name

DanPatterson — Sun, 14 Feb 2021 22:58:37 GMT

Code formatting on the esri Community will help

Code formatting ... the Community Version - GeoNet, The Esri Community

Re: Removing characters from a Feature Class file name

MichaelTomiak — Sun, 14 Feb 2021 23:11:14 GMT

Thanks. Worked well. Didn't know indentation was required for it to run. Thought it was a presentation aspect.

WRT to the last line of code, what function could replace this so that it was only renaming the original files, rather than making a copy of the data (which is useful sometimes) but I do not have much data storage capacity left. Making a copy might be tight.

Would it be something like:
arcpy.RenameRaster_management (ras, newrastername)

Re: Removing characters from a Feature Class file name

Anonymous User — Sun, 14 Feb 2021 23:15:31 GMT

Simple oneliner for fun, IF the 25 characters are all the same.

newrastername = ras.replace('THISIS25CHARACTERSLONGMAN', 'Hello')

Re: Removing characters from a Feature Class file name

MichaelTomiak — Sun, 14 Feb 2021 23:16:00 GMT

Cheers Dan. This is really helpful as I am definitely not a coder and learning/applying only the very basics of Python to help me with the GIS aspect of my technical work.

I used Rename tool for this with %Name% in the output name field originally, but that's only helpful for appending information and not (as my original Question suggestions) that helpful for removing, or slicing up filenames.

Re: Removing characters from a Feature Class file name

DavidPike — Sun, 14 Feb 2021 23:32:39 GMT

import arcpy #import os #youre not using os so dont import it dir = r'C:\Users\X\Desktop\X\X.gdb' arcpy.env.workspace = dir for ras in arcpy.ListRasters ("*"): #print (ras) #original raster name #print(ras.split("*")) basename = ras[25:] #strips the first 25 characters from original raster name newrastername = "Hello" + basename print (newrastername) arcpy.Rename_management(ras, newrastername) #rename raster with the new/updated name

Re: Removing characters from a Feature Class file name

MichaelTomiak — Mon, 15 Feb 2021 00:49:17 GMT

Worked a treat 😀- thanks for your time and effort David. Saved me an awful lot of manual renaming tonight.