Preventing Python toolbox refreshing?

Question

I developed a Python toolbox in ArcGIS 10.3. Everything in this toolbox works correctly. I just have one problem: Every time I click on the value table (ex:click 1 in below image), then click on anywhere in toolbox (ex:click 2) the toolbox and data frame are refreshed. It's very annoying for users. The refreshing process continues until the user closes the toolbox. Refreshing is enabled after select a feature (select by attribute in my code). How can I get rid of refreshing toolbox?

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I edited my code. I used SearchCursor to list values in value tables and used SelectByAttribute function outside the if statement.As @Hornbydd mentioned the problem is SelectByAttribute.I think if SelectByAttribute runs only once then if parameters[0].value altered, this function run again The refresh problem will solve.But how to force SelectByAttribute to run once ?

import arcpy
class Toolbox(object):
 def __init__(self):
 """Define the toolbox (the name of the toolbox is the name of the
 .pyt file)."""
 self.label = "Toolbox"
 self.alias = ""
 # List of tool classes associated with this toolbox
 self.tools = [Tool]
class Tool(object):
 def __init__(self):
 """Define the tool (tool name is the name of the class)."""
 self.label = "b"
 self.description = ""
 self.canRunInBackground = False
 def getParameterInfo(self):
 """Define parameter definitions"""
 # line point parameter
 params0 = arcpy.Parameter(
 displayName="Line point",
 name="line_point",
 datatype="GPFeatureLayer",
 parameterType="Optional",
 direction="Input")
 params0.filter.list = ["Polyline"]
 # point parameter
 params1 = arcpy.Parameter(
 displayName="point",
 name="point_point",
 datatype="GPFeatureLayer",
 parameterType="Optional",
 direction="Input")
 params1.filter.list = ["POINT"]
 # Table
 params2 = arcpy.Parameter(
 displayName="Table",
 name="table",
 datatype="GPTableView",
 parameterType="Required",
 direction="Input")
 # line code
 params3 = arcpy.Parameter(
 displayName="Line Code",
 name="Line_Code",
 datatype="GPLong",
 parameterType="Required",
 direction="Input")
 # Direction
 params4 = arcpy.Parameter(
 displayName="Direction",
 name="Direction",
 datatype="GPString",
 parameterType="Required",
 direction="Input")
 params4.filter.type="ValueList"
 # value table
 params5 = arcpy.Parameter(
 displayName='Values',
 name='values',
 datatype='GPValueTable',
 parameterType='Required',
 direction='Input')
 # Table output
 params6 = arcpy.Parameter(
 displayName="Tableoutput",
 name="tableoutput",
 datatype="GPTableView",
 parameterType="Derived",
 direction="Output")
 params6.parameterDependencies = [params2.name]
 params5.columns = [['Long', 'point Code'],['GPString','point Name'],['GPString','Rank']]
 params5.filters[2].type="ValueList"
 params = [params0,params1,params2,params3,params4,params5,params6]
 return params
 def isLicensed(self):
 """Set whether tool is licensed to execute."""
 return True
 def updateParameters(self, parameters):
 fielddelimi1 = arcpy.AddFieldDelimiters(parameters[0].value, "Number")
 sql_exp1 = "{0} = {1}".format(fielddelimi1,parameters[3].value)
 fielddelimi2 = arcpy.AddFieldDelimiters(parameters[0].value, "PathType")
 sql_exp2 = u"{0} = '{1}'".format(fielddelimi2,u'\u0631\u0641\u062a')
 sqlfinal = u"%s AND %s"%(sql_exp1,sql_exp2)
 arcpy.SelectLayerByAttribute_management(parameters[0].valueAsText,"NEW_SELECTION",where_clause= sqlfinal)
 if parameters[0].value and parameters[1].value and parameters[2].value and parameters[3].altered :
 def valuetable():
 if not parameters[5].altered :
 with arcpy.da.SearchCursor(parameters[2].valueAsText,["Number","pointUniqueCode","pointRow"],where_clause = sqlfinal) as curtable:
 vtab = []
 for rowt in curtable:
 vtab.append([rowt[0],rowt[1],rowt[2]])
 parameters[5].value = vtab
 with arcpy.da.SearchCursor(parameters[0].valueAsText,"Number",where_clause = sql_exp1) as curpoint :
 l2 = [valuetable() for row in curpoint if row[0] == parameters[3].value]
 return
 def updateMessages(self, parameters):
 """Modify the messages created by internal validation for each tool
 parameter. This method is called after internal validation."""
 return
 def execute(self, parameters, messages):
 """The source code of the tool."""
 if parameters[5].altered :
 fields = [f for f in parameters[5].value]
 UniqueCode = [f[0] for f in parameters[5].value]
 rankslist = zip(*fields)[-1]
 i = 0
 with arcpy.da.UpdateCursor(parameters[6].valueAsText,["pointUniqueCode","pointRow"]) as cur:
 for row in cur:
 row[1] = rankslist[i]
 cur.updateRow(row)
 i+=1
 return

• Hornbydd: I have a feeling that this behaviour is outside your control and is being called internally by the SelectLayerByAttribute tools. No idea this will work so give it a go, try setting the environment setting addOutputsToMap to False? The logic is if you are not adding to Map then no need to refresh?
• PolyGeo: Your question seems to have changed since it was first asked. Now, while it has no answers is the ideal time to heavily revise it to try and make what you are now asking clear.

Answer 1

Once the user has altered a parameter, the "altered" property will always be true, but the "hasBeenValidated" parameter is only false until the first run through the updateParameters routine after they edit the value. You might want to check for that instead.

if not parameters[3].hasBeenValidated:
 arcpy.SelectLayerByAttribute_management(parameters[0].valueAsText,"NEW_SELECTION",where_clause= sqlfinal)

The attribute in question is described on this help page: http://pro.arcgis.com/en/pro-app/arcpy/geoprocessing_and_python/customizing-tool-behavior-in-a-python-toolbox.htm