There is no REST API support in ONTAP until version 9.6 so the Python client library (netapp-ontap) does not support running against versions prior to that.
Perhaps you are looking for the NMSDK which does include Python bindings against the ONTAPI APIs which worked against these older versions of ONTAP. You can find information and downloads for that on the support site. Here's a link that I found: https://mysupport.netapp.com/site/products/all/details/netapp-manageability-sdk/downloads-tab
