class asdf.ExternalArrayReference(fileuri, target, dtype, shape)[source]

Bases: object

Store a reference to an array in an external File.

This class is a simple way of referring to an array in another file. It provides no way to resolve these references, that is left to the user. It also performs no checking to see if any of the arguments are correct. e.g. if the file exits.

fileuri: `str`

The path to the path to be referenced. Can be relative to the file containing the reference.

target: `object`

Some internal target to the data in the file. Examples may include a HDU index, a HDF path or an asdf fragment.

dtype: `str`

The (numpy) dtype of the contained array.

shape: `tuple`

The shape of the array to be loaded.


>>> import asdf
>>> ref = asdf.ExternalArrayReference("myfitsfile.fits", 1, "float64", (100, 100))
>>> tree = {'reference': ref}
>>> with asdf.AsdfFile(tree) as ff:
...     ff.write_to("test.asdf")