topic Re: Feature class name wildcard in Python Questions

Feature class name wildcard

CCWeedcontrol — Sat, 11 Dec 2021 19:00:54 GMT

I have a feature class table that i need to export to excel, the feature class will be created weekly. The problem i am having is that on creation the feature class gets the date added to the end of the feature class name and i am trying to access with a wildcard because the date will change based on when the feature class gets created. How can i get the feature class with a wildcard?

import arcpy  
 
workspace = "Database Servers\GIS.gds\GISSERVER1 (VERSION:dbo.DEFAULT)" 
arcpy.env.workspace = workspace

'''
lyrs = ['Hyrdo_FINAL_ALL_*']  
for fc in arcpy.ListFeatureClasses():  
    for lyr in lyrs:  
        if fc.startswith(lyr):
            print 'lyr'
'''
lyr = "Hyrdo_FINAL_ALL_*" #Database Servers\GIS.gds\GISSERVER1 (VERSION:dbo.DEFAULT)\Hyrdo_FINAL_ALL_121817
arcpy.MakeFeatureLayer_management(lyr, "In_memory\lyr1")

arcpy.TableSelect_analysis("In_memory\lyr1","C:/Temp/Export_Output.xls", "")


print 'done'‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Re: Feature class name wildcard

MicahBabinski — Sat, 11 Dec 2021 19:00:57 GMT

Hi CC,

ListFeatureClasses has an optional wildcard parameter I think you could use.

arcpy.env.workspace = r"[path to your workspace]"
lyr = arcpy.ListFeatureClasses("Hyrdo_FINAL_ALL_*")[0]
# do something with lyr‍‍‍

By the way, I don't think an excel file is a valid output to TableSelect. If you just want to write the table to an excel spreadsheet you could do:

arcpy.TableToExcel_conversion(lyr, r"[path].xls")‍

Hope this helps!

Micah

Re: Feature class name wildcard

RandyBurton — Sat, 11 Dec 2021 19:00:59 GMT

First, I would use a date format that is suitable for sorting: YYMMDD. Append this to your feature names when backing up. You can then append the feature name to a list (if it starts with, contains, etc. what you are looking for) when you loop through a ListFeatureClasses or ListLayers, sort the list and then pick the first or last item in the sorted list as the oldest or newest.

features = ['Hyrdo_FINAL_ALL_171218','Hyrdo_FINAL_ALL_171012',
            'My_Feature_170101', 'Another_Feature_161012']
found = []

for feature in features:
    if feature.startswith('Hyrdo_FINAL_ALL_'): # assumes this is name up to date
        found.append(feature)

found.sort()
print found[-1:]
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Re: Feature class name wildcard

CCWeedcontrol — Thu, 21 Dec 2017 22:21:10 GMT

I am getting "list index out of range" at lyr = arcpy.ListFeatureClasses("Hyrdo_FINAL_ALL_*") [0]?

thanks for the TableToExcel.

Re: Feature class name wildcard

DanPatterson_Retired — Thu, 21 Dec 2017 22:25:38 GMT

did you then try Randy's suggestion of 'startswith' that would be the next extension... assuming Hyrdo is the correct spelling and not Hydro

Re: Feature class name wildcard

MicahBabinski — Thu, 21 Dec 2017 22:26:54 GMT

Hmmm, it's possible that would due to a typo. Is the spelling "Hyrdo_FINAL_ALL_..." or "Hydro_FINAL_ALL_..."?

Also, is the old feature class deleted and replaced by the date-stamped new copy, or is a date-stamped new copy added to the workspace? If there is a stack of them going back multiple weeks you might need to parse the date field like Randy said to find the newest one.

Micah

Re: Feature class name wildcard

CCWeedcontrol — Thu, 21 Dec 2017 23:35:40 GMT

Yes Hydro, sorry. The feature class gets delete and replace with a new one with the date it was created, sorry i should have mentioned that.

Re: Feature class name wildcard

DanPatterson_Retired — Thu, 21 Dec 2017 23:38:34 GMT

did you fix this

lyr = "Hyrdo_FINAL_ALL_*" #Database Servers\GIS.gds\GISSERVER1 (VERSION:dbo.DEFAULT)\Hyrdo_FINAL_ALL_12181

and try it again given the spelling error (or is it?)

Re: Feature class name wildcard

CCWeedcontrol — Thu, 28 Dec 2017 16:20:17 GMT

Fixing the typo didn't not fix it the "list index out of range" error.

Re: Feature class name wildcard

DanPatterson_Retired — Sat, 11 Dec 2021 19:01:02 GMT

that error message is only returned when there is an empty list...

for example

a = []   # define an empty list

a[0]     # slice the empty list and get an error

Traceback (most recent call last):

  File "<ipython-input-18-6a1284577a36>", line 1, in <module>
    a[0]

IndexError: list index out of range‍‍‍‍‍‍‍‍‍‍

Now you say... but the list isn't empty...

Another way to get the error

a = [1,2]  # so now we have 2 elements in the list... 

a[2]       # so let's get the second

Traceback (most recent call last):

  File "<ipython-input-21-fc907be37984>", line 1, in <module>
    a[2]

IndexError: list index out of range‍‍‍‍‍‍‍‍‍‍

But python is zero-indexed, so if you want the second, then you have to slice by [1], since [0] returns the first.

That's how slicing works... it is either empty or you sliced beyond the range, or you sliced wrong.

Re: Feature class name wildcard

CCWeedcontrol — Sat, 11 Dec 2021 19:01:05 GMT

I was able to get it to work by removing the feature_dataset [0] and making the workspace a "database connection" not a direct connection.

import arcpy
from arcpy import env

arcpy.env.workspace = "Database Connections\GISSERVER1 (VERSION:dbo.DEFAULT)"

lyr = arcpy.ListFeatureClasses ("Hydro_FINAL_ALL_*")#Database Servers\GIS.gds\GISSERVER1 (VERSION:dbo.DEFAULT)\Hyrdo_FINAL_ALL_121817
for fc in lyr:
    arcpy.MakeFeatureLayer_management(fc, "In_memory\lyr1")
    arcpy.TableSelect_analysis("In_memory\lyr1","C:/Temp/Export_Output.xls", "")
    #arcpy.FeatureClassToFeatureClass_conversion("In_memory\lyr1","C:\Temp","Export.shp")


print 'done'
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