The Databricks SDK for Python has a built-in current_user API.

Below is an example in a Notebook source file:

# Databricks notebook source
# MAGIC %pip install --upgrade databricks-sdk
# MAGIC
# MAGIC dbutils.library.restartPython()

# COMMAND ----------

from databricks.sdk import WorkspaceClient

w = WorkspaceClient()

me2 = w.current_user.me()

print(me2)

https://databricks-sdk-py.readthedocs.io/en/latest/getting-started.html

https://databricks-sdk-py.readthedocs.io/en/latest/workspace/iam/current_user.html