Re-use `sep` in `posixpath.expanduser()`

[nineteendo]

Feature or enhancement

Proposal:

We can replace root with the already assigned sep from earlier:

if isinstance(path, bytes):
    userhome = os.fsencode(userhome)
-    root = b'/'
-else:
-    root = '/'
-userhome = userhome.rstrip(root)
-return (userhome + path[i:]) or root
+userhome = userhome.rstrip(sep)
+return (userhome + path[i:]) or sep

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

• Remove _get_[both]sep[s]() calls in os.path #117634

Linked PRs

• gh-118119: Re-use sep in posixpath.expanduser() #118120