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Adds a custom warning message (severity of 1) to the messages of a script tool or Python toolbox tool.

When a tool is run, arcpy is fully aware of the application it is called from. One major effect of this is that you can write messages in Python and your messages automatically appear on the tool dialog box, in the history, and the Python window.


AddWarning (message)
ParameterExplanationData Type

The warning message to add.


Code sample

AddWarning example

Add a custom warning message to a script tool.

import arcpy

fc = arcpy.GetParameterAsText(0)

# Get the count from GetCount's Result object
feature_count = int(arcpy.GetCount_management(fc).getOutput(0))

if feature_count == 0:
    arcpy.AddWarning("{0} has no features.".format(fc))
    arcpy.AddMessage("{0} has {1} features.".format(fc, feature_count))

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