littlefs for Python

littlefs-python provides a thin wrapper around littlefs, a filesystem targeted for small embedded systems. The wrapper provides a pythonic interface to the filesystem and allows the creation, inspection and modification of the filesystem or individual files. Even if this package uses Cython, the goal is not to provide a high performance implementation. Cython was chosen as an easy method is offered to generate the binding and the littlefs library in one step.

Quick Examples

Let's create a image ready to transfer to a flash memory using the pythonic interface:

from littlefs import LittleFS

# Initialize the File System according to your specifications
fs = LittleFS(block_size=512, block_count=256)

# Open a file and write some content
with fs.open('first-file.txt', 'w') as fh:
    fh.write('Some text to begin with\n')

# Dump the filesystem content to a file
with open('FlashMemory.bin', 'wb') as fh:
    fh.write(fs.context.buffer)

The same can be done by using the more verbose C-Style API, which closely resembles the steps which must be performed in C:

from littlefs import lfs

cfg = lfs.LFSConfig(block_size=512, block_count=256)
fs = lfs.LFSFilesystem()

# Format and mount the filesystem
lfs.format(fs, cfg)
lfs.mount(fs, cfg)

# Open a file and write some content
fh = lfs.file_open(fs, 'first-file.txt', 'w')
lfs.file_write(fs, fh, b'Some text to begin with\n')
lfs.file_close(fs, fh)

# Dump the filesystem content to a file
with open('FlashMemory.bin', 'wb') as fh:
    fh.write(cfg.user_context.buffer)

Installation

As littlefs is bundled with the package you will need to install the correct version of this package in successfully read or create images for your embedded system. If you start from scratch the latest version is recommended.

LittleFS Version	Package Version	LittleFS File System Version
2.9.0	v0.11.X	2.0 / 2.1 [1]
2.9.0	v0.10.X	2.0 / 2.1 [1]
2.8.0	0.8.X-0.9.X	2.0 / 2.1 [1]
2.7.0	0.7.X	2.0 / 2.1 [1]
2.7.0	0.6.X	2.0 / 2.1 [1]
2.6.1	0.5.0	2.1
2.2.1	0.4.0	2.0
2.2.1	0.3.0	2.0

[1]	(1, 2, 3, 4, 5) See `test/test_multiversion.py` for examples.

This is as simple as it can be:

pip install littlefs-python

At the moment wheels (which require no build) are provided for the following platforms, on other platforms the source package is used and a compiler is required:

Linux: Python 3.7 - 3.12 / x86_64, arm64
MacOS: Python 3.7 - 3.12 / x86_64, arm64
Windows: Python 3.7 - 3.12 / 32- & 64-bit

CLI

littlefs-python comes bundled with a command-line tool, littlefs-python, that can be used to create and extract littlefs binary images.

$ littlefs-python --help
usage: littlefs-python [-h] [--version] {create,extract,list} ...

Create, extract and inspect LittleFS filesystem images. Use one of the
commands listed below, the '-h' / '--help' option can be used on each command
to learn more about the usage.

optional arguments:
  -h, --help            show this help message and exit
  --version             show program's version number and exit

Available Commands:
  {create,extract,list}
    create              Create LittleFS image from file/directory contents.
    extract             Extract LittleFS image contents to a directory.
    list                List LittleFS image contents.

To create a littlefs binary image:

# Creates a 1-megabyte "lfs.bin" containing README.rst
$ littlefs-python create README.rst lfs.bin --fs-size=1mb --block-size=4096

# Creates a 1-megabyte "lfs.bin" containing the contents of the examples/ folder
$ littlefs-python create examples lfs.bin --fs-size=1mb --block-size=4096

To extract the contents of a littlefs binary image:

$ littlefs-python extract lfs.bin output/ --block-size=4096

Development Setup

Start by checking out the source repository of littlefs-python:

git clone https://github.com/jrast/littlefs-python.git

The source code for littlefs is included as a submodule which must be checked out after the clone:

cd <littlefs-python>
git submodule update --init

this ensures that the correct version of littlefs is cloned into the littlefs folder. As a next step install the dependencies and install the package:

pip install -r requirements.txt
pip install -e .

It's highly recommended to install the package in a virtual environment!

Development Hints

Test should be run before committing: pytest test
Mypy is used for typechecking. Run it also on the tests to catch more issues: mypy src test test/lfs
Mypy stubs can be generated with stubgen src. This will create a out directory containing the generated stub files.

Creating a new release

NEW (with github deploy action):

Make sure the master branch is in the state you want it.
Create a new tag with the correct version number and push the tag to github
Start the "Build and Deploy Package" workflow for the created tag on github

OUTDATED (without github deploy action):

Make sure the master branch is in the state you want it.
Create a tag with the new version number
Wait until all builds are completed. A new release should be created automatically on github.
Build the source distribution with python setup.py sdist.
Download all assets (using ci/download_release_files.py).
Upload to pypi using twine: twine upload dist/*.