gfal2-python 1.13.0
Python3 bindings for Gfal2
License: Apache 2
Keywords: gfal2, grid, dmc, data management clients

Gfal2-Python
============

``gfal2-python`` is a C++ library offering a thin layer of Python
wrappers via ``PyBoost``. We recommend installing it via RPMs, but it is
also available on
`PyPI/gfal2-python <https://pypi.org/project/gfal2-python/>`__.

Using the Gfal2 Python Bindings
-------------------------------

The Gfal2 Python bindings are intended to be easy to use.

Pre-requisites
^^^^^^^^^^^^^^

Before jumping into usage, ensure you have a proxy certificate available
in the default location (``/tmp/x509up_u$(id -u)``).

Optionally, you may want to install relevant Gfal2 protocol plugins. Our
example will use HTTP protocol, so we must ensure we have the Gfal2 HTTP
plugin installed:

.. code:: bash

   $ dnf install -y gfal2-plugin-http

Examples
^^^^^^^^

Example of stating a file location:

.. code:: python

   import gfal2

   ctx = gfal2.creat_context()
   ctx.stat("https://eospublic.cern.ch/eos/opstest/dteam/file.test")

Example of copying a file from local to remote:

.. code:: python

   import gfal2

   ctx = gfal2.creat_context()
   ctx.filecopy("file:///tmp/file.test", "https://eospublic.cern.ch/eos/opstest/dteam/file.test")
   ctx.stat("https://eospublic.cern.ch/eos/opstest/dteam/file.test")

Example of copying the file from remote to local (with custom transfer
parameters):

.. code:: python

   import gfal2

   ctx = gfal2.creat_context()
   params = ctx.transfer_parameters()
   params.set_checksum = ("both", "adler32", None)
   params.overwrite = True

   ctx.filecopy("https://eospublic.cern.ch/eos/opstest/dteam/file.test", "file:///tmp/file.test")
   ctx.checksum("file:///tmp/file.test", "adler32")

Further code examples can be found in the
`example/python/ <https://github.com/cern-fts/gfal2-python/tree/v1.12.2/example/python>`__
source directory.

Installing via Pip
------------------

Installing the package via ``pip install gfal2-python`` will reproduce
the compilation process, hence why you need to make sure you have all
the right dependencies. This guide details the steps needed to get all
the dependencies, starting from a *blank* machine.

This guide assumes you have the EPEL repositories installed
(``epel-release`` package). In this example, the build platform is
``Alma9`` and we will use ``v1.12.2``, but the same process applies for
other versions or build platforms.

.. code:: bash

   # Clone the gfal2-python repository with the desired version (example for v1.12.2)
   $ git clone --branch v1.12.2 https://github.com/cern-fts/gfal2-python.git
   $ cd gfal2-python/

   # Install standard set of build packages
   $ ./ci/fedora-packages.sh

   # Build the source RPM and install dependencies
   $ cd packaging/
   $ make srpm
   $ dnf builddep -y gfal2-python-*.src.rpm

   # Ready to install now from PyPI
   $ pip install gfal2-python

Useful links
------------

-  DMC documentation: https://dmc-docs.web.cern.ch/dmc-docs/
-  Apache License, version 2.0:
   https://www.apache.org/licenses/LICENSE-2.0
-  Issue tracking: https://github.com/cern-fts/gfal2-python/issues
-  Support channels: dmc-support@cern.ch
-  Development team contact: dmc-devel@cern.ch

Enjoy using the Gfal2 Python bindings!