Working with a path-based resource system, the application needs to find the first working resource that manages a given resource based on paths. I need a succinct, pythonic way to generate the following:
Input:
/house/dogs/ralph/bone
Output:
/house/dogs/ralph/bone
/house/dogs/ralph
/house/dogs
/house
Note: It's okay to use os.path
or similar built-ins, but these are not filesystem resources. Output can be anything iterable (list, set, generator, etc.).
Use pathlib
. PurePath
s offer an abstract interface to path-like objects that have no relationship to the file system. In particular, PurePosixPath
is the kind that uses forward slashes (/
) as separators:
>>> from pathlib import PurePosixPath
>>> p = PurePosixPath('/house/dogs/ralph/bone')
>>> str(p.parent)
/house/dogs/ralph
>>> str(p.parent.parent)
/house/dogs
You can loop this easily:
p = PurePosixPath(...)
while str(p) != p.root:
# Do stuff to p
p = p.parent
A fairly pythonic finishing touch would be to make it a generator:
def receding_path(p):
p = PurePosixPath(p)
while str(p) != p.root:
yield str(p)
p = p.parent
for item in receding_path('/house/dogs/ralph/bone'):
# do stuff to each item