that @0.8.0 is just an artifact - I copied those lines from somewhere.
I am not very familiar with dsteem or JS in general, either.

How do you get beem to work, then ?

from beem.blockchain import Blockchain
from beem import Steem
from beem.instance import set_shared_steem_instance

blockchain = Blockchain()
print(blockchain.get_current_block_num())

testnet = Steem(node=["https://testnet.steemdev.com:2001"])
set_shared_steem_instance(testnet)

blockchain2 = Blockchain()
print(blockchain2.get_current_block_num())

This does not work either, I tried variations of the url with port and without and http https ...