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I want to be able to set the value of a field to Null using python, but I get an error. I am using arcpy.CalculateField_management

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Can you provide a sample of your code and the error message? – Brian May 9 '13 at 15:42
You do not say what your data format is. If your source dataset is a shapefile then you cannot set the field to Null as dBase format does not support it. – Hornbydd May 9 '13 at 16:31

Not using field-calculator, you can use UpdateCursor and setNull. (Arcgis for 10.1)

a quick example:

rows = arcpy.UpdateCursor(fc, sql, etc...)
for row in rows:
del rows
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Great!, but I am using Arc 10.0 and we are not moving to 10.1 or awhile. – Rob Smith Jul 16 '13 at 20:26
It's about the same in 10.0. The same method will work. – gm70560 Jul 17 '13 at 21:43

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