https://community.esri.com/t5/python-questions/python-toolbox-only-validate-when-you-press-run/m-p/1541901#M72924 <P>You can just rename your validation function so it's not called in the validation loop and run it at the top of your execute function, something like this:</P><P>&nbsp;</P><LI-CODE lang="python">import arcpy import time class Tool: ... # other methods def validateParameters(self, parameters): # Expensive validation goes here time.sleep(5) # Randomly fail validation if time.time() % 2 == 0: arcpy.AddError("Validation failed") return False arcpy.AddMessage("Validation complete") return True def execute(self, parameters, messages): # Expensive execution goes here (after run) if not self.validateParameters(parameters): arcpy.AddError("Validation failed") return return</LI-CODE><P>&nbsp;</P> Tue, 24 Sep 2024 13:41:17 GMT HaydenWelch 2024-09-24T13:41:17Z https://community.esri.com/t5/python-questions/python-toolbox-only-validate-when-you-press-run/m-p/1539655#M72888 <P>I'm running into an issue where the standard validation is just taking waaaay too long (Describing the input) and I really just need it to validate when I press Run, not beforehand.</P><P>That is, if there's an error, only tell me when I press Run.</P><P>Has anyone figured out a way to do this?</P><P>&nbsp;</P> Tue, 17 Sep 2024 18:58:31 GMT https://community.esri.com/t5/python-questions/python-toolbox-only-validate-when-you-press-run/m-p/1539655#M72888 AlfredBaldenweck 2024-09-17T18:58:31Z https://community.esri.com/t5/python-questions/python-toolbox-only-validate-when-you-press-run/m-p/1541901#M72924 <P>You can just rename your validation function so it's not called in the validation loop and run it at the top of your execute function, something like this:</P><P>&nbsp;</P><LI-CODE lang="python">import arcpy import time class Tool: ... # other methods def validateParameters(self, parameters): # Expensive validation goes here time.sleep(5) # Randomly fail validation if time.time() % 2 == 0: arcpy.AddError("Validation failed") return False arcpy.AddMessage("Validation complete") return True def execute(self, parameters, messages): # Expensive execution goes here (after run) if not self.validateParameters(parameters): arcpy.AddError("Validation failed") return return</LI-CODE><P>&nbsp;</P> Tue, 24 Sep 2024 13:41:17 GMT https://community.esri.com/t5/python-questions/python-toolbox-only-validate-when-you-press-run/m-p/1541901#M72924 HaydenWelch 2024-09-24T13:41:17Z