Way to find out Azure user name using Python SDK

I'm trying to programatically find out the user name of the Azure account running a script. Use case is to log certain info to user specific directories in default datastore.
I can find the info using Azure CLI, running on a compute instance, e.g.
`az account show` returns a JSON which has `user.name` attribute. Is there any equivalent API in the Python SDK?

此 issue 未指定任何 repository 檔案、測試或 SDK 進入點。先檢查 Python SDK 如何驗證正在執行的 Azure 帳戶，並與 `az account show` 比較；識別或記錄一種為計算執行個體使用情境取得 `user.name` 的等效方式，即算完成。

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