What's the best way to change assignee of an issue using jira python library?

[Rohan Lele]

Hello,

I am trying to use the jira python library (https://pypi.org/project/jira/) to access JIRA REST API. 

I want to change the assignee of an issue using the username/email address. From what I understood, we need the accountId for changing assignee now. 

But I only know the user's name and email address. How to get the accountId from the name/email address to use it to change the assignee.

Pls help.

Thanks.