Adding Combobox to Python Toolbox tool dialog?

Question

I am trying to create a Python Toolbox tool which is supposed to add two fields State and StateAbb to selected Shapefile from selected combobox.

How I can add a Combobox which contains a list of US states to the Tool?

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 = "states"
 self.alias = "states"
 # List of tool classes associated with this toolbox
 self.tools = [states]
class states(object):
 def __init__(self):
 self.label = "states Tool"
 self.description = "Add and Insert Value from Combo"
 self.canRunInBackground = False
 def getParameterInfo(self):
 param0 = arcpy.Parameter(
 displayName="1- State Street Layer",
 name="in_features",
 datatype="GPFeatureLayer",
 parameterType="Optional",
 direction="Input"
 )
 params = [param0]
 return params
 def execute(self, params, messages):
 """The source code of the tool."""
 arcpy.AddField_management(params[0],"area","TEXT","#","#","#","#","NULLABLE","NON_REQUIRED","#")
 arcpy.CalculateField_management(params[0],"area","!shape.area@squaremeters!","PYTHON_10.3","#")
 return

• NULL.Dude: can you explain what a combo-box is?
• PolyGeo: You are using a Python Toolbox tool not a Python Script tool.
• user2856: @Geo.Dude en.wikipedia.org/wiki/Combo_box

Answer 1

Use a "Value List"

param.filter.type = "ValueList"
param.filter.list = [a, list, of, states]

E.g.

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 = "states"
 self.alias = "states"
 # List of tool classes associated with this toolbox
 self.tools = [States]
class States(object):
 def __init__(self):
 self.label = "states Tool"
 self.description = "Add and Insert Value from Combo"
 self.canRunInBackground = False
 self.states = {'Alabama': 'AL', 'Alaska': 'AK', 'Arizona': 'AZ', 'Arkansas': 'AR', 
 'California': 'CA', 'Colorado': 'CO', 'Connecticut': 'CT', 
 'Delaware': 'DE', 'Florida': 'FL', 'Georgia': 'GA', 'Hawaii': 'HI', 
 'Idaho': 'ID', 'Illinois': 'IL', 'Indiana': 'IN', 'Iowa': 'IA', 
 'Kansas': 'KS', 'Kentucky': 'KY', 'Louisiana': 'LA', 'Maine': 'ME', 
 'Maryland': 'MD', 'Massachusetts': 'MA', 'Michigan': 'MI', 
 'Minnesota': 'MN', 'Mississippi': 'MS', 'Missouri': 'MO', 
 'Montana': 'MT', 'Nebraska': 'NE', 'Nevada': 'NV', 'New Hampshire': 'NH', 
 'New Jersey': 'NJ', 'New Mexico': 'NM', 'New York': 'NY', 
 'North Carolina': 'NC', 'North Dakota': 'ND', 'Ohio': 'OH', 'Oklahoma': 'OK', 
 'Oregon': 'OR', 'Pennsylvania': 'PA', 'Rhode Island': 'RI', 
 'South Carolina': 'SC', 'South Dakota': 'SD', 'Tennessee': 'TN', 
 'Texas': 'TX', 'Utah': 'UT', 'Vermont': 'VT', 'Virginia': 'VA', 
 'Washington': 'WA', 'West Virginia': 'WV', 'Wisconsin': 'WI', 
 'Wyoming': 'WY', 'American Samoa': 'AS', 'District of Columbia': 'DC', 
 'Guam': 'GU', 'Northern Mariana Islands': 'MP', 'Puerto Rico': 'PR', 
 'United States Virgin Islands': 'VI'}
 def getParameterInfo(self):
 param0 = arcpy.Parameter(
 displayName="1- State Street Layer",
 name="in_features",
 datatype="GPFeatureLayer",
 parameterType="Optional",
 direction="Input"
 )
 param1 = arcpy.Parameter(
 displayName="State",
 name="state",
 datatype="GPString",
 parameterType="Required",
 direction="Input")
 # Set a value list of States (and other US areas)
 param1.filter.type = "ValueList"
 param1.filter.list = sorted(self.states.keys())
 params = [param0, param1]
 return params
 def execute(self, params, messages):
 """The source code of the tool."""
 state = params[1].valueAsText
 abbr = self.states[state]
 #Do something with state and abbr
 return