1

I know this question has been answered but I am not seeing an adaptation that I can understand. I am trying to use a numeric variable in a where clause and just having a hard time figuring it out.

fc1 = "L:\ENGINEERING\collind\ArcGIS\Default.gdb\sedaSampleHistory"

fieldname = "pocid"

delimfield = arcpy.AddFieldDelimiters(fc1, fieldname)

pocidCnt = 3

cursor = arcpy.da.SearchCursor(fc1, ["pocid", "cl2total"], delimfield + " = pocidCnt ")

I have tried all kinds of ways to get pocidCnt to work in the where clause and I am not having any luck. If I write it as

cursor = arcpy.da.SearchCursor(fc1, ["pocid", "cl2total"], delimfield + " = 3 ")

it works fine.

What am I doing wrong?

  • Have you tried not passing it as a string in quotes and just putting the variable name with no quotes:-------cursor = arcpy.da.SearchCursor(fc1, ["pocid", "cl2total"], delimfield + pocidCnt ) – landocalrissian Aug 22 '14 at 17:02
  • Thanks for the quick response... when I make that change I get Runtime error Traceback (most recent call last): File "<string>", line 10, in <module> TypeError: coercing to Unicode: need string or buffer, int found – cdd Aug 22 '14 at 17:08
5

Your code fails because the variable name (pocidCnt) is inside a string and is therefore being taken literally: the final query being used is "pocid" = pocidCnt, where pocidCnt is clearly not a number that can be matched. You can substitute the value represented by the pocidCnt variable into the query string in the following ways:

cursor = arcpy.da.SearchCursor(fc1, ["pocid", "cl2total"], delimfield + " = " + str(pocidCnt))

or, preferably:

cursor = arcpy.da.SearchCursor(fc1, ["pocid", "cl2total"], "{0} = {1}".format(delimfield, pocidCnt))
  • Thank you. Both of those work. So I guess what I was trying to do was insert an int into an expression that is a string. Is that correct? – cdd Aug 22 '14 at 17:13
  • Yes, the value of pocidCnt must be converted from an int to a string (i.e. from 3 to "3") before it can be combined with the rest of the query string. The str() function achieves this clumsily, while the string .format() method is a little more graceful about it. – nmpeterson Aug 22 '14 at 17:16

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