topic Re: Another da.SearchCursor Issue in Python Questions

Another da.SearchCursor Issue

JoeBorgione — Sun, 12 Dec 2021 03:00:59 GMT

Just when I thought I had cursors figured out....

I have a small test table (4 records) that I apply arcpy.MakeTableView_management to. Then I run a simple search cursor:

>>> fields = ["Type","StreetName"]
>>> with arcpy.da.SearchCursor("view",fields) as cursor:
...     for row in cursor:
...         if "'{}'".format(row[0]) == "'{}'".format("Junk"):
...            print "'{},{}'".format(row[1],row[0]) 
...            
'BUCKMAN,Junk'
‍‍‍‍‍‍‍

The print statement returns the one row that meets the conditional. Cool....

But I want to select that one single record. If I swap out the print statement with :

arcpy.SelectLayerByAttribute_management("view","NEW_SELECTION")
‍

All 4 records get selected. In fact if I run it like this:

>>> with arcpy.da.SearchCursor("view",fields) as cursor:
...     for row in cursor:
...         if "'{}'".format(row[0]) == "'{}'".format("Junk"):
...            print "'{},{}'".format(row[1],row[0]) 
...            arcpy.SelectLayerByAttribute_management("view","NEW_SELECTION")
...            
'BUCKMAN,Junk'
‍‍‍‍‍‍‍

You can see it prints just the fields from the record that meets the conditional, but all four records get selected. It's gotta be a (simple) Joe thing, but I'm missing it....

Dan Patterson‌

Joshua Bixby‌

Re: Another da.SearchCursor Issue

JamesCrandall — Wed, 15 Nov 2017 17:13:24 GMT

Your select by attribute needs a where clause added.

http://pro.arcgis.com/en/pro-app/tool-reference/data-management/select-layer-by-attribute.htm#ESRI_USAGES_54F55D13A48F460096A074E2B55C3850

Re: Another da.SearchCursor Issue

JoshuaBixby — Wed, 15 Nov 2017 17:15:54 GMT

Cursors are aware of selections on views and layers, but the tools that select records on views and layers are not aware of cursors. If you create a new selection on a view or layer with no SQL clause, it selects all the records.

Re: Another da.SearchCursor Issue

JoeBorgione — Wed, 15 Nov 2017 17:22:48 GMT

Thanks guys. I knew it was a Joe oversight.