PurePath.relative_to() fails in 3.6

[DeaD_EyE]

From docs:

Note

Although os.path.relpath() and PurePath.relative_to() have some overlapping use-cases, their semantics differ enough to warrant not considering them equivalent.

You can use monkey patching.

from pathlib import Path
from os.path import relpath

Path.relpath = lambda self, start=None: Path(relpath(self, start))

# or define a function
def rp(self, start=None):
    return Path(relpath(self, start))
# Path.relpath = rp

my_path = Path.home() / '.local' / 'bin'
rel = my_path.relpath('/var/log/nginx')
print(my_path)
print(rel)

Output:
/home/deadeye/.local/bin
../../../home/deadeye/.local/bin

Windows:

from pathlib import Path
from os.path import relpath
from os import environ


Path.relpath = lambda self, start=None: Path(relpath(self, start))
 
# or define a function
def rp(self, start=None):
    return Path(relpath(self, start))
# Path.relpath = rp

# Windows has some special Paths stored in environment variables
PROGRAMFILES = Path(environ['PROGRAMFILES'])
LOCALAPPDATA = Path(environ['LOCALAPPDATA'])


rel_prog_path = 'Testprogramm/data'
curdir = PROGRAMFILES / rel_prog_path 
target = LOCALAPPDATA / rel_prog_path 

print(curdir)
print(target)
print(target.relpath(curdir))

Maybe someone can try this on Mac. I don't have Mac.
I guess it's similar to UNIX.