S3FS
====

S3FS is a `PyFilesystem <https://www.pyfilesystem.org/>`__ interface to
Amazon S3 cloud storage.

As a PyFilesystem concrete class,
`S3FS <http://fs-s3fs.readthedocs.io/en/latest/>`__ allows you to work
with S3 in the same way as any other supported filesystem.

Installing
----------

You can install S3FS from pip as follows:

::

    pip install fs-s3fs

Opening a S3FS
--------------

Open an S3FS by explicitly using the constructor:

.. code:: python

    from fs_s3fs import S3FS
    s3fs = S3FS('mybucket')

Or with a FS URL:

.. code:: python

      from fs import open_fs
      s3fs = open_fs('s3://mybucket')

Downloading Files
-----------------

To *download* files from an S3 bucket, open a file on the S3 filesystem
for reading, then write the data to a file on the local filesystem.
Here's an example that copies a file ``example.mov`` from S3 to your HD:

.. code:: python

    from fs.tools import copy_file_data
    with s3fs.open('example.mov', 'rb') as remote_file:
        with open('example.mov', 'wb') as local_file:
            copy_file_data(remote_file, local_file)

Although it is preferable to use the higher-level functionality in the
``fs.copy`` module. Here's an example:

.. code:: python

    from fs.copy import copy_file
    copy_file(s3fs, 'example.mov', './', 'example.mov')

Uploading Files
---------------

You can *upload* files in the same way. Simply copy a file from a source
filesystem to the S3 filesystem. See `Moving and
Copying <https://docs.pyfilesystem.org/en/latest/guide.html#moving-and-copying>`__
for more information.

ExtraArgs
---------

S3 objects have additional properties, beyond a traditional filesystem.
These options can be set using the ``upload_args`` and ``download_args``
properties. which are handed to upload and download methods, as
appropriate, for the lifetime of the filesystem instance.

For example, to set the ``cache-control`` header of all objects uploaded
to a bucket:

.. code:: python

    import fs, fs.mirror
    s3fs = S3FS('example', upload_args={"CacheControl": "max-age=2592000", "ACL": "public-read"})
    fs.mirror.mirror('/path/to/mirror', s3fs)

see `the Boto3
docs <https://boto3.readthedocs.io/en/latest/reference/customizations/s3.html#boto3.s3.transfer.S3Transfer.ALLOWED_UPLOAD_ARGS>`__
for more information.

``acl`` and ``cache_control`` are exposed explicitly for convenience,
and can be used in URLs. It is important to URL-Escape the
``cache_control`` value in a URL, as it may contain special characters.

.. code:: python

    import fs, fs.mirror
    with open fs.open_fs('s3://example?acl=public-read&cache_control=max-age%3D2592000%2Cpublic') as s3fs
        fs.mirror.mirror('/path/to/mirror', s3fs)

S3 URLs
-------

You can get a public URL to a file on a S3 bucket as follows:

.. code:: python

    movie_url = s3fs.geturl('example.mov')

Documentation
-------------

-  `PyFilesystem Wiki <https://www.pyfilesystem.org>`__
-  `S3FS Reference <http://fs-s3fs.readthedocs.io/en/latest/>`__
-  `PyFilesystem
   Reference <https://docs.pyfilesystem.org/en/latest/reference/base.html>`__