Generic python toolbox template for ArcGIS

toolbox_template.pyt

# ----------------------------------------------------------------------------
# Name:         My tool
# Purpose:      TODO
#
# Author:       Jon Morris
#
# Created:      2017
# Copyright:    MY COMPANY 2017
# Licence:      ArcGIS for Desktop Advanced
# ----------------------------------------------------------------------------

import arcpy


class LicenseError(Exception):
    pass


class Toolbox(object):
    def __init__(self):
        """Define the toolbox (the name of the toolbox is the name of the
        .pyt file)."""
        self.label = "My toolbox"
        self.alias = ""

        # List of tool classes associated with this toolbox
        self.tools = [MyTool]


class MyTool(object):
    def __init__(self):
        """Define the tool (tool name is the name of the class)."""
        self.label = "My tool"
        self.description = "TODO"
        self.canRunInBackground = True
        arcpy.env.overwriteOutput = True
        # arcpy.CheckOutExtension("Spatial")

    def getParameterInfo(self):
        """Define parameter definitions"""
        # # First parameter
        # param0 = arcpy.Parameter(
            # displayName="Input Param 1",
            # name="in_param_1",
            # datatype="GPString",
            # parameterType="Required",
            # direction="Input")

        # # Second parameter
        # param1 = arcpy.Parameter(
            # displayName="Output Param 1",
            # name="out_param_1",
            # datatype="GPString",
            # parameterType="Optional",
            # direction="Output")

        # param0.value = "default value"

        # params = [param0, param1]
        params = None
        return params

    def isLicensed(self):
        """Set whether tool is licensed to execute."""
        # try:
        #     if arcpy.CheckExtension("Spatial") != "Available":
        #         raise LicenseError
        # except LicenseError:
        #     return False  # tool cannot be executed

        return True  # tool can be executed

    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."""

        try:
            OUTWorkspace = arcpy.env.scratchGDB
            #MyParam = parameters[0].value

            arcpy.env.workspace = OUTWorkspace
            arcpy.env.extent = arcpy.Extent(-180.0, -90.0, 180.0, 90.0)

            arcpy.AddWarning('Generic warning')
            #parameters[1].value = MyParam

            # Refresh Catalog

            arcpy.RefreshCatalog(OUTWorkspace)

        except Exception, e:
            arcpy.AddError(e.message)
        # finally:
        #     arcpy.CheckInExtension("Spatial")
        return

Just update the tool name and doc, uncomment license/param details and add your script to the execute method.