Hi Shweta,
The AdWordsUserListService can be used to manage and create user lists. However, it is currently not possible to Remove the complete user list using the AdWordsUserListService.mutate() as the REMOVE operator is not supported. You may refer to this sample on how to create and populate a user list in Python.
Please let me know if you have further clarifications.
Regards,
Hiroyuki
Google Ads API Team