Subscriptable Path

A subclass of Python's pathlib objects that allow subscripting/indexing.

I was recently working with some pathlib.Path stuff and found that I wanted to get the nth folder in a deep path. Naively, I tried:

>>> from pathlib import Path
>>> a = Path("/foo/bar/baz/a/b/c/d.txt")
>>> a[4]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'PosixPath' object is not subscriptable

Harrumph.

This project aims to make such a thing possible. See Usage for details.

Installation

This is a pure python package with no dependencies. Installing is easy:

pip install subscriptable_path

Usage

Note: Initial versions modify pathlib.PurePath directly, as those classes are a bit of a pain to subclass (because of tricks with __new__). This means that importing this module will affect every usage of pathlib.PurePath. Future work will adjust this API so that you can use pathlib.PurePath and SubscriptablePath simultaneously.

The goal is to create a SubscriptablePath object that can be imported and replace the pathlib.Path object or can be used alongside. Eg:

from subscribtable_path import SubscriptablePath as Path  # drop-in replacement
from subscriptable_path import SubscriptablePath as SPath  # use alongside

It's easiest to show usage with examples:

>>> from subscriptable_path import Path

# Instantiate a Path object, just like `pathlib.Path`:
>>> path = Path("/mnt/foo/bar/1/2/3")

# Get a component of the path:
>>> path[2]
"foo"
>>> path[0]
"/"
>>> path[-1]
"3"

# Slices are also supported for __getitem__
>>> path[1:3]
"mnt/foo"

# Check the path length:
>>> len(path)
7

# Adjust a particular component, modifying the object
>>> path[2] = "hello"
>>> path
Path("/mnt/hello/bar/1/2/3")

# Delete a part of the path, modifying the object
>>> del path[2]
>>> path
Path("/mnt/bar/1/2/3")

# loop through the items in the path
>>> for name in path:
...     print(name)
...
"/"
"mnt"
"bar"
"1"
"2"
"3"

# Reverse the path:
# Note that if the path is absolute, the root is kept.
>>> reversed(path)
>>> path
Path("/3/2/1/bar/mnt")

>>> rel_path = Path("1/2/3")
>>> reversed(rel_path)
>>> rel_path
Path("3/2/1")

# And check if an item is in the path:
>>> "foo" in path
False
>>> "bar" in path
True
>>> "ba" in path
False

Development

1. Clone the repo: git clone https://github.com/dougthor42/subscriptable-path
2. Move into that dir: cd subscriptable-path
3. Create a virtual environment: python -m venv .venv
4. Activate it: . .venv/bin/activate
5. Install python packages:
   1. pip install -U pip setuptools wheel
   2. pip install -r requirements-dev.txt
   3. pip install -e .
6. Run tests to verify: pytest
7. Install pre-commit hooks: pre-commit install
8. Ready to develop

Deployment

TODO: Move to fully automated deployment with GitHub Actions.

1. Update the version in pyproject.toml
2. Create a new git tag: git tag v<version>.
3. python -m build
4. pip install twine
5. twine upload dist/*

Changelog

See CHANGELOG.md.