pathlib_next

A robust, extensible pathlib-like base for any resource addressable as a path or URI. Same method names, signatures, semantics, and exception types as pathlib.Path wherever a pathlib.Path equivalent exists -- write code once against Path/UriPath and it works against your local disk, an in-memory tree, an HTTP index, or an SFTP server. Every intentional divergence from pathlib's behavior is documented, not silent -- see docs/divergences.md.

Features

Every scheme shares the same glob(), walk(), copy()/move(), rm() implementations -- see the full matrix and notes in Schemes.

• Unified path interface across local files, in-memory paths, archive members, and file/data/ftp/http/dav/sftp/s3 URIs.
• MemPath -- a lightweight virtual filesystem for mocks, tests, or transient storage.
• PathSyncer -- one-way checksum-driven tree sync between any two Path implementations, with dry-run and event hooks.
• Query/Source -- parse and serialize URL query strings and URI authority components.
• Extensible two ways: subclass Path directly for a custom non-URI resource, or subclass UriPath for a new URI scheme -- see Extending.

Installation

pip install pathlib_next

Optional features/extras:

import pathlib_next and LocalPath/MemPath work with no extras installed; data:, ftp(s):, and zip:/tar: only need the uri extra (they're stdlib-based otherwise).

Quick start

Local filesystem -- drop-in pathlib.Path:

from pathlib_next import Path

p = Path("./data") / "report.txt"
p.write_text("hello")
print(p.read_text())

In-memory (mem:) -- a virtual filesystem, no disk I/O:

from pathlib_next.mempath import MemPath

p = MemPath("/config/settings.json")
p.parent.mkdir(parents=True, exist_ok=True)
p.write_text('{"debug": true}')

file: -- the same local filesystem, addressed as a URI:

from pathlib_next.uri import UriPath

p = UriPath("file:./data/report.txt")
print(p.read_text())

http(s): -- read files and list Apache/nginx-style directory indexes:

from pathlib_next.uri import UriPath

p = UriPath("http://example.com/data/")
for child in p.iterdir():
    if child.is_file():
        print(child.name, child.stat().st_size)

sftp: -- same interface, over SSH:

from pathlib_next.uri import UriPath

p = UriPath("sftp://user@host/var/log/app.log")
print(p.read_text())

zip:/tar: -- address a member inside an archive (Java-style !/ separator; the archive half is itself any URI -- file:, http:, sftp:, ...):

from pathlib_next.uri import UriPath

member = UriPath("zip:file:./backup.zip!/etc/config.ini")
print(member.read_text())

Also built in: data: (RFC 2397 inline payloads), ftp(s): (stdlib ftplib), dav(s): (WebDAV, full read/write over HTTP), and s3: (boto3) -- one example per scheme in Schemes.

Extending

Two first-class ways to add a new path-addressable resource -- both covered in depth, with worked examples, in Extending:

• Subclass Path directly for a custom, non-URI resource (MemPath is the reference exemplar).
• Subclass UriPath and set __SCHEMES for a new URI scheme (FileUri/ HttpPath/SftpPath are the built-in examples).

pathlib_next.testing provides reusable pytest mixins (PurePathContract, ReadPathContract, and PathContract) covering the baseline contracts for various levels of capabilities -- subclass one of them with a root fixture to verify your own implementation.

API overview

Supported Python versions

Python >= 3.9, tested on 3.9 and 3.13 in CI (see .github/workflows/test.yml).

Development

pip install -e ".[dev,uri,http,sftp,sftp-async]"
pytest -q

If you maintain separate virtual environments per Python version locally (e.g. .venv/3.9/, .venv/3.13/), run the same pytest -q in each -- CI does the equivalent across Python 3.9/3.13 on Linux, macOS, and Windows.

Benchmarks

Run the benchmark suite using:

python benchmarks/bench.py

A benchmark report and methodology notes live in docs/benchmarks.md.

Releasing

This project follows Semantic Versioning and keeps a CHANGELOG.md. Pushing a tag matching v* triggers the release workflow: test gate → build → publish → docs deploy.

Documentation site

MkDocs builds the API reference from docs/, published on every release. To preview locally: mkdocs serve.

License

MIT — see LICENSE.