But that's a perfectly valid filename:

$ mkdir -p adl://myblob.azuredatalakestore.net/local/abc/xyz
$ ls -R adl:
'adl:':
myblob.azuredatalakestore.net/

'adl:/myblob.azuredatalakestore.net':
local/

'adl:/myblob.azuredatalakestore.net/local':
abc/

'adl:/myblob.azuredatalakestore.net/local/abc':
xyz/

'adl:/myblob.azuredatalakestore.net/local/abc/xyz':

The pathlib module isn't going to guess whether you passed it a filename or URI of some sort, especially when it's a valid filename. That's the caller's job to get right.

Removing the double slashes is a normal part of pathlib's behavior of normalizing paths, just as if you said from a bash shell "ls //etc//sysconfig", which will show the contents of "/etc/sysconfig". Although I'll admit I couldn't find this documented anywhere with a quick search.