topic 'NoneType' object has no attribute 'utf_8_decode' from generateToken in Python Questions

'NoneType' object has no attribute 'utf_8_decode' from generateToken

VincentLantaca — Fri, 22 Jan 2021 17:11:29 GMT

I have a published geoprocessing service that is being used by web app builder. This geoprocessing service makes a call to an ArcGIS REST Service. The code first requests for a token so that it can use the REST service to add features to a feature class.

There are intermittent issues with the function used to get a token for the REST service where the user can get an error:

'NoneType' object has no attribute 'utf_8_decode'

This is the function:

# get access token from the arcgis rest server def get_token(username, password, protocol, arcgis_server_url): token_url = "{protocol}{host}".format( protocol=protocol, host=arcgis_server_url ) + r'/tokens/generateToken' params = { 'username': username, 'password': password, "client": "requestip", 'f': 'json' } headers = {'Content-Type': 'application/x-www-form-urlencoded'} response = requests.post(token_url, data=params, headers=headers) if response.status_code == 200: if 'token' in response.json(): return response.json()['token'] else: error_msg = 'An error occurred while trying to create an access token. Check login info. Aborting.' arcpy.AddError(error_msg) arcpy.SetParameterAsText(13, error_msg) sys.exit() else: error_msg = 'An error occurred while trying to get access token. Aborting.' arcpy.AddError(error_msg) arcpy.SetParameterAsText(13, error_msg) sys.exit()

I have the call to this function in a try except block:

try: token = get_token(username, password, protocol, arcgis_server_url) except Exception as e: output_msg = str(e)

By using debug print statements, I found that it fails on the request post

response = requests.post(token_url, data=params, headers=headers)

Example parameters:

username: username password: password protocol = https:// arcgis_server_url = server-name.com/server

I have also verified that regardless of whether or not get_token fails, the input parameters are the same.

I have found that sometimes when the issue starts occurring, I can temporarily fix the issue by restarting the geoprocessing service. I am using ArcGIS Server: 10.5.1 with Python 2.7.16

Has anyone run into this problem?

Re: 'NoneType' object has no attribute 'utf_8_decode' from generateToken

JoshuaBixby — Fri, 22 Jan 2021 21:59:36 GMT

In this line:

headers = {'Content-Type': 'application/x-www-form-urlencoded'}

you say the content is URL-encoded, but I don't see you actually encoding it anywhere.

Since you are using Python 2.x, see the getToken example at Scripting languages and the ArcGIS REST API—ArcGIS Server | Documentation for ArcGIS Enterprise

Re: 'NoneType' object has no attribute 'utf_8_decode' from generateToken

VincentLantaca — Mon, 25 Jan 2021 17:33:28 GMT

If I'm not mistaken, requests will automatically convert the dictionary:

https://requests.kennethreitz.org/en/master/user/quickstart/#more-complicated-post-requests

I will try using httplib and urllib and see if that helps, but it is still unclear why the script fails sometimes and works other times.

Re: 'NoneType' object has no attribute 'utf_8_decode' from generateToken

JoshuaBixby — Mon, 25 Jan 2021 19:17:13 GMT

Testing with httplib and urllib will eliminate that automagical conversion as a source of the problem.

Re: 'NoneType' object has no attribute 'utf_8_decode' from generateToken

VincentLantaca — Tue, 26 Jan 2021 22:49:44 GMT

I've tried adding:

params = urllib.urlencode(params)

before the the call to request.post and I still ran into the error

Re: 'NoneType' object has no attribute 'utf_8_decode' from generateToken

VincentLantaca — Wed, 27 Jan 2021 00:32:51 GMT

I am noticing that CPU and Memory usage can be high when this happens, I am still not 100% sure that is the cause though.