filesystem_spec

A specification for pythonic filesystems.

Install

pip install fsspec

would install the base fsspec. Various optionally supported features might require specification of custom extra require, e.g. pip install fsspec[ssh] will install dependencies for ssh backends support. Use pip install fsspec[full] for installation of all known extra dependencies.

Up-to-date package also provided through conda-forge distribution:

conda install -c conda-forge fsspec

Purpose

To produce a template or specification for a file-system interface, that specific implementations should follow, so that applications making use of them can rely on a common behaviour and not have to worry about the specific internal implementation decisions with any given backend. Many such implementations are included in this package, or in sister projects such as s3fs and gcsfs.

In addition, if this is well-designed, then additional functionality, such as a key-value store or FUSE mounting of the file-system implementation may be available for all implementations "for free".

Documentation

Please refer to RTD

Develop

fsspec uses GitHub Actions for CI. Environment files can be found in the "ci/" directory. Note that the main environment is called "py38", but it is expected that the version of python installed be adjustable at CI runtime. For local use, pick a version suitable for you.

# For a new environment (mamba / conda).
mamba create -n fsspec -c conda-forge  python=3.9 -y
conda activate fsspec

# Standard dev install with docs and tests.
pip install -e ".[dev,doc,test]"

# Full tests except for downstream
pip install s3fs
pip uninstall s3fs
pip install -e .[dev,doc,test_full]
pip install s3fs --no-deps
pytest -v

# Downstream tests.
sh install_s3fs.sh
# Windows powershell.
install_s3fs.sh

Testing

Tests can be run in the dev environment, if activated, via pytest fsspec.

The full fsspec suite requires a system-level docker, docker-compose, and fuse installation. If only making changes to one backend implementation, it is not generally necessary to run all tests locally.

It is expected that contributors ensure that any change to fsspec does not cause issues or regressions for either other fsspec-related packages such as gcsfs and s3fs, nor for downstream users of fsspec. The "downstream" CI run and corresponding environment file run a set of tests from the dask test suite, and very minimal tests against pandas and zarr from the test_downstream.py module in this repo.

Code Formatting

fsspec uses Black to ensure a consistent code format throughout the project. Run black fsspec from the root of the filesystem_spec repository to auto-format your code. Additionally, many editors have plugins that will apply black as you edit files. black is included in the tox environments.

Optionally, you may wish to setup pre-commit hooks to automatically run black when you make a git commit. Run pre-commit install --install-hooks from the root of the filesystem_spec repository to setup pre-commit hooks. black will now be run before you commit, reformatting any changed files. You can format without committing via pre-commit run or skip these checks with git commit --no-verify.