Python - azure-devops - AssignedTo field is missing

Question

I wrote a python function retrieving the results from an ADO query

def get_query_results(connection, project_name,query_id):

   '''
   Gets the result of a query in ADO
   '''
   results = []
   try:
      wit_client = connection.clients.get_work_item_tracking_client()
      result = wit_client.query_by_id(query_id)

      work_items = result.work_items

      for work_item in work_items:
         work_item_details = wit_client.get_work_item(id=work_item.id, fields=["System.Id", "System.Title","System.AssignedTo"], expand="Relations,Fields")
         results.append({"id": work_item_details.fields['System.Id'], "title": work_item_details.fields['System.Title'], "assigned_to": work_item_details.fields['System.AssignedTo']})
   except Exception as e:
        logger.exception(f'Error fetching repositories from {project_name}: {str(e)}')

   return results

but although there are a lot of available fields like "Assigned To" in ADO ui, it seems I cannot get AssignedTo field

results.append({"id": work_item_details.fields['System.Id'], "title": work_item_details.fields['System.Title'], "assigned_to": work_item_details.fields['System.AssignedTo']})
KeyError: 'System.AssignedTo'

• how can I fix this ?
• how can I retrieve the available fields instead of just guessing ?

thanks for your help

Answer 1

When using the function "wit_client.get_work_item" to get a work item in Python, if this work item is not assigned to any user, the output of the function will not contain the 'System.AssignedTo' field. In this situation, the "work_item_details.fields['System.AssignedTo']" will return the error message "KeyError: 'System.AssignedTo'".

To avoid this error, you can try to use the function like as below.

work_item = wit_clinet.get_work_item(xxx)
work_item_assigned_to = work_item.fields.get('System.AssignedTo')

• If the work item has been assigned to a user, it will return the content of 'System.AssignedTo'.
• If the work item is not assigned to any user, it will return 'None' instead of an error.

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EDIT:

Below is the Python script sample I tested on my side, and it can work well as stated above:

from azure.devops.connection import Connection
from msrest.authentication import BasicAuthentication

personal_access_token = '{personal_access_token}'
organization_url = 'https://dev.azure.com/{organization}'
query_id = '{query_id}'

credentials = BasicAuthentication('', personal_access_token)
connection = Connection(base_url=organization_url, creds=credentials)

wit_clinet = connection.clients.get_work_item_tracking_client()
query_result = wit_clinet.query_by_id(query_id)

work_items = query_result.work_items
for wit in work_items:
    print('--------------------------------------------------------------')
    print(f'Getting work item by Id: {wit.id}')
    work_item = wit_clinet.get_work_item(id=wit.id, fields=["System.Id", "System.Title","System.AssignedTo"], expand="Relations,Fields")
    work_item_assigned_to = work_item.fields.get('System.AssignedTo')
    print(work_item_assigned_to)

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