minidir: Minimal directory interface and implementation

The minimal interface for directories and files and two implementations: in-memory and real file system versions.

It's a good choice when we want to separate file-access side effects from pure functional part of our code base.

Installation

Already published on Pypi

pip install minidir

Usage

• Interface: Directory -> Path, File
  • Directory is the container where we access File by Path
• Implementation
  • SystemDirectory: a Directory backed by real file system.
  • FakeDirectory: a Directory only exists in-memory.

Some error like NameCollision and NotFound will be raised in corresponding situations.

Example:

import minidir

class SomeClass:
    folder: minidir.Directory

    def __init__(self, folder: minidir.Directory) -> None:
        # inject directory to separate side effect from core logic
        pass

def main():
    # use actual file system during production
    instance = SomeClass(minidir.SystemDirectory("/path/to/root"))

def test_some_class():
    # use in-memory implementation during test
    instance = SomeClass(minidir.FakeDirectory())

Future Work

• Implementations for network-oriented storage, e.g. WebDAV, S3, Dropbox ...
• Stream based file read / write interface.