I'm working with ArcGIS 10.2. I used this code to select one record of an attribute table:

import arcpy
# Set the workspace
env.workspace = "F:ArcGIS\Trab\Model\Lin_150_tr.shp"
# Make a layer from the feature class
arcpy.MakeFeatureLayer_management("Lin_150_tr", "lyr5") 

arcpy.SelectLayerByAttribute_management("lyr5", "NEW_SELECTION", ' "FID" = 2 ')

And it works! Now I need to select no one record but some records of the same table, so I used a list of values and a loop:

import arcpy
env.workspace = "F:ArcGIS\Trab\Model\Lin_150_tr.shp"
arcpy.MakeFeatureLayer_management("Lin_150_tr", "lyr5")  

for a in crit_150: 
    arcpy.SelectLayerByAttribute_management("lyr5", "NEW_SELECTION", ' "FID" = a ')

But it gives me an error:

Runtime error  Traceback (most recent call last):   File "<string>", line 21, in <module>   File "c:\program files (x86)\arcgis\desktop10.2\arcpy\arcpy\management.py", line 6494, in SelectLayerByAttribute     raise e ExecuteError: ERROR 000358: Invalid expression Failed to execute (SelectLayerByAttribute).

How can I do this?


Instead of hard coding the list of values (like @GISGe), I would build a string and pass it as variable:

import arcpy
arcpy.MakeFeatureLayer_managemen(r"F:\ArcGIS\Trab\Model\Lin_150_tr.shp", "lyr5")   

crit_150_str = ','.join(str(val) for val in crit_150)
arcpy.SelectLayerByAttribute_management("lyr5", "NEW_SELECTION", '"FID" IN ({})'.format(crit_150_str))
  • 1
    Str(tuple(crit)) will do the job without join etc – FelixIP Aug 29 '16 at 19:42
  • @FelixIP: this only works if the list has more than one element. If not the output would be e.g.: "('2',)", which is no correct SQL.That's why I would prefer my solution, since it is more generic. – Saleika Aug 31 '16 at 5:58

a is considered as part of the string ' "FID" = a '. The variable a shouldn't be part of the string expression. Instead you can use this notation for example, making use of the python string.format() function:

arcpy.SelectLayerByAttribute_management("lyr5", "NEW_SELECTION", """"FID" = {}""".format(a))

I doubt the field delimiters are necessary here, """FID = {}""".format(a) is probably fine as well.


If you want to select to select all rows with values from your list at once, use this expression:

import arcpy
arcpy.MakeFeatureLayer_management(r"F:ArcGIS\Trab\Model\Lin_150_tr.shp", "lyr5")  

arcpy.SelectLayerByAttribute_management("lyr5", "NEW_SELECTION", """FID IN (2,10,200,323,349,384,433)""")
  • Now it runs, without error but it doesn't show the different records, shows only the first.. And I confirmed tis when I open the table "lyr5", where only appears one row.. – S.Rai Aug 29 '16 at 11:25
  • What you're doing is iterating over the values in your crit_150 list, and selecting one record at a time. If you want to select all values at once you should modify the expression, I'll add it to my answer – GISGe Aug 29 '16 at 11:30
  • Yes, I need to select all this values at the same time – S.Rai Aug 29 '16 at 11:32
  • It continues to do just the first value and I need a way to run the list and show all values of this list.. – S.Rai Aug 29 '16 at 11:48

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