dirct

A dict that reflects the contents of a directory.

Installation

You can install this package with pip.

$ pip install dirct

Links

Usage

Basic usage

>>> from dirct import Dirct
>>> d = Dirct("path/to/directory")
>>> from typing import Mapping
>>> isinstance(d, Mapping)
True

Loading files

The directory may contain any number of files and subdirectories. Files ending in .toml, .json, .yaml, and .yml are parsed correctly according to their respective formats, and all other files are read as text if it can be decoded or as bytes otherwise.

You can also pass custom loader callables to the loaders parameter of the Dirct constructor. A loader callable takes the Path to a file and returns the value that file represents. The DEFAULT_LOADERS constant contains loaders for the aforementioned file formats.

from dirct import Dirct, DEFAULT_PARSERS

def csv_loader(path: Path) -> Sequence[Mapping[str, str]]:
	with path.open() as f:
		return tuple(csv.DictReader(f))

Dirct("path/to/directory", loaders=(csv_loader, *DEFAULT_LOADERS))

Loaders are tried in order. If a loader raises an UnsupportedFileError then the next loader is tried. If a loader raises any other type of Exception it is propagated. If no loader can load a file, then an UnsupportedFileError is raised.

Example directory

Consider the following directory path/to/directory/ that contains data about a video game.

path/to/directory/
├── __self__.toml
├── publisher.toml
├── version
└── levels/
	├── castle.lvl.json
	├── dungeon.lvl.json
	└── forest.lvl.json

Creating a Dirct with this directory would produce a mapping with the following structure.

>>> d = Dirct("path/to/directory").to_dict()
{
	"name": "Dungeons, Dungeons, and More Dungeons", # From __self__.toml
	"release_date": datetime.date(2021, 1, 1), # From __self__.toml
	"version": "1.0.0",
	"publisher.toml": {
		"name": "Probabilitor the Annoying",
		"founded": 2015
	},
	"levels": {
		"castle.lvl.json": {
			"name": "Castle",
			"enemies": ["goblin", "orc", "ogre"]
		},
		"dungeon.lvl.json": {
			"name": "Dungeon",
			"enemies": ["skeleton", "zombie", "ghost"]
		},
		"forest.lvl.json": {
			"name": "Forest",
			"enemies": ["wolf", "bear", "dragon"]
		}
	}
}

Mapping files to/from keys

Converting between file names and dictionary keys is handled by a KeyMapper object, which can be passed to the key_mapper argument of the Dirct constructor.

Exact key mapper (default)

The exact key mapper only recognizes keys that exactly match the file/directory names.

>>> from dirct import ExactKeyMapper
>>> d = Dirct("path/to/directory", key_mapper=ExactKeyMapper())
>>> tuple(d.keys())
('publisher.toml', 'version', 'levels')
>>> d["publisher.toml"] # Gets the contents of publisher.toml
{'name': 'Probabilitor the Annoying', 'founded': 2015}
>>> d["publisher"]
KeyError: 'publisher'
>>> d[".publisher.toml"]
KeyError: '.publisher.toml'
>>> d["publisher.json"]
KeyError: 'publisher.json'

Basename key mapper

The basename key mapper ignores leading dots and all trailing extensions. If hidden=False is passed to the constructor, then leading dots are not ignored.

In case of a name collision when mapping a key to a path, an AmbiguityError is raised unless strict=False was passed to the constructor, in which case a warning is logged and one of the paths is chosen. (For a given directory's contents, the same path will be chosen consistently.)

>>> d = Dirct("path/to/directory") # Default key mapper
>>> tuple(d.keys())
('publisher', 'version', 'levels')
>>> d["publisher"] # Gets the contents of publisher.toml
{'name': 'Probabilitor the Annoying', 'founded': 2015}
>>> d["publisher.toml"] # Also works
{'name': 'Probabilitor the Annoying', 'founded': 2015}
>>> d[".publisher.foo.json"] # Also works because the leading dot and file extensions are ignored
{'name': 'Probabilitor the Annoying', 'founded': 2015}

__self__

A directory may contain a single special file called __self__.* with any known extension. The contents of this file are parsed to a dictionary (an InvalidSelfError is raised if it can't be parsed as a dictionary) which is then merged with the rest of the directory's contents (explicit files/subdirectories take precedence over __self__.*). This allows you to keep some of the keys in a single file and the rest in separate files or subdirectories.

For example, __self__.toml may contain the following:

name = "Dungeons, Dungeons, and More Dungeons"
release_date = 2021-01-01

>>> d = Dirct("path/to/directory")
>>> d["name"]
'Dungeons, Dungeons, and More Dungeons'