This is a sample filter for a long data type in Python.

SampleTBX.pyt

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 = "ToolboxSample"
        self.alias = "ToolboxSample"

        # 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 = "Tool"
        self.description = ""
        self.canRunInBackground = False

    def getParameterInfo(self):
        """Define parameter definitions"""

        # Input Features parameter
        in_value = arcpy.Parameter(
            displayName="Input Value",
            name="in_value",
            datatype="GPLong",
            parameterType="Required",
            direction="Input")

        in_value.filter.type = "ValueList"
        in_value.filter.list = [1,10,100]
        
        params = [in_value]
        return params

    def isLicensed(self):
        """Set whether tool is licensed to execute."""
        return True

    def updateParameters(self, parameters):
        """Modify the values and properties of parameters before internal
        validation is performed.  This method is called whenever a parameter
        has been changed."""
        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."""
        return