It doesn't support modern DMs, just the original NIP-04. I haven't found any Python implementation that does, and I don't trust my own skills enough to try

There is a Python wrapper to rust-nostr. It is the most capable lib I know. https://pypi.org/project/nostr-sdk/

i use https://rust-nostr.org/

Is lightweight and maintained, the feature set is limited and the API might change https://github.com/spesmilo/electrum-aionostr