topic Re: Projected datasets in one single line using a script tool in Python Questions

Projected datasets in one single line using a script tool

AhmedAldossary — Sat, 15 Oct 2011 03:01:40 GMT

Hi,

I'm writing a script in python to re-project a set of shapefiles, and I want to report these re-projected shapefiles in a geoprocessing message in "a single line" seperated by commas with no trailing comma at the end, after processing the script tool. I used arcpy.AddMessage(), however, it reported the results in separate lines. I would like to mention that I used a loop here to list all features inside workspace i.e. ListFeatureClasses()

Does anyone have any idea of doing that?

Re: Projected datasets in one single line using a script tool

JakeSkinner — Fri, 10 Dec 2021 21:37:07 GMT

I was able to do this by appending the feature classes to a list, writing the list to a text file, reading the text file as a string while removing the last comma, and then finally writing the string using the arcpy.AddMessage function. Here is an example of how to do this with a list of feature classes:

import arcpy, os
from arcpy import env
env.workspace = r"C:\temp\python\test.gdb"

# Create an empty list
list = []

# Create a text file
output = open(r"C:\temp\python\list.txt", "w")

lstFCs = arcpy.ListFeatureClasses("*")
for fc in lstFCs:
    list.append(fc)

# write each feature class to the text file
for n in list:
    output.write(n + " ")

# read the text file and add commas
output = open(r"C:\temp\python\list.txt", "r")

s = output.read()
s = s.rstrip()
s = s.replace(" ", ", ")

arcpy.AddMessage(s)

# close and delete the text file
output.close()
os.remove(r"C:\temp\python\list.txt")

Re: Projected datasets in one single line using a script tool

AhmedAldossary — Mon, 17 Oct 2011 13:04:28 GMT

Thank you Jake for your help. You gave me an idea of to use a list to display the feature classes, although I took a different approach instead of writing feature classes to a text file. To explain more, after the loop, I convert the list to string using:
x = ", ".join(myList)
Then I used that in the geoprocessing tool as follows:
arcpy.AddMessage("Projected " + str(x))

Again, thank you for your help!

Re: Projected datasets in one single line using a script tool

JakeSkinner — Mon, 17 Oct 2011 13:11:47 GMT

Awesome, your method will be much easier! I was having trouble figuring out how to convert a list to a string. Thanks for the syntax:

x = ", ".join(myList)

Re: Projected datasets in one single line using a script tool

EvanEchlin — Mon, 03 Nov 2014 23:27:13 GMT

Ahmed,

Thanks for the guidance here. I am looking to achieve the same goal with the script results separated by a comma. When I use the syntax;

myList = reprojectedFCs

x = ", ".join(myList)

arcpy.AddMessage("Projected " + str(x))

I end up with commas before and after every single letter - instead of after each feature class. I am new to scripting, any idea what I am doing wrong here?

Thanks,

Evan

Re: Projected datasets in one single line using a script tool

NeilAyres — Wed, 05 Nov 2014 08:11:20 GMT

if myList contains only 1 object ie len(myList) == 1 then join, split etc indeed any list function will interate through the individual components.

So just check first if len(myList) > 1, before using ",".join(myList)