IO_BACKENDS

sherpa.astro.io.IO_BACKENDS: dict[str, ModuleType] = {'astropy': <module 'sherpa.astro.io.pyfits_backend' from '/home/docs/checkouts/readthedocs.org/user_builds/sherpa/conda/4.18.0/lib/python3.10/site-packages/sherpa/astro/io/pyfits_backend.py'>, 'dummy': <module 'sherpa.astro.io.dummy_backend' from '/home/docs/checkouts/readthedocs.org/user_builds/sherpa/conda/4.18.0/lib/python3.10/site-packages/sherpa/astro/io/dummy_backend.py'>, 'pyfits': <module 'sherpa.astro.io.pyfits_backend' from '/home/docs/checkouts/readthedocs.org/user_builds/sherpa/conda/4.18.0/lib/python3.10/site-packages/sherpa/astro/io/pyfits_backend.py'>}

global list of all successfully imported I/O backends