fsspec / fsspec/filesystem_spec

ArrowFSWrapper._strip_protocol differs from pure fsspec implementation

Open
#1,137 3 comments 2 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

Dominant language
Python
Stars
1.4k
Forks
490
Avg merge
2d 3h
Merged PRs (30d)
38

Description

Not sure if this is a "bug", but I ran into this discrepancy in https://github.com/dask/dask/pull/9699 for a local Windows filesystem, and needed to add an explicit workaround. Therefore, I'd like to establish what the "correct" behavior should be.

Reproducer:

from fsspec.implementations.local import LocalFileSystem
from fsspec.implementations.arrow import ArrowFSWrapper
from pyarrow.fs import LocalFileSystem as PALocalFileSystem

path = "C:\\MyPath\\to\\fake.parquet"
fs = LocalFileSystem()
fs_aw = ArrowFSWrapper(PALocalFileSystem())
print("Pure fsspec:", fs._strip_protocol(path))
print("Wrapped pyarrow:", fs_aw._strip_protocol(path))

Output:

Pure fsspec: /home/nfs/rzamora/workspace/cudf-23.02/dask/C:\MyPath\to\fake.parquet
Wrapped pyarrow: C:\MyPath\to\fake.parquet

Question: What should _strip_protocol return in this case?

Contributor guide

No contributing guide indexed for this repository

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Run the provided reproducer and compare LocalFileSystem._strip_protocol with ArrowFSWrapper._strip_protocol for the Windows-style path. Determine and document the intended return value, then add regression coverage for the agreed behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
python
Domain
backend
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
35/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.