Importing from Photutils

Photutils functionality is organized into subpackages that must be imported explicitly. Importing only the top-level photutils package will not expose its tools. For example, the following code will fail:

>>> import photutils
>>> aper = photutils.CircularAperture((10, 20), r=4)
AttributeError: module 'photutils' has no attribute 'CircularAperture'

Instead, you must import tools from their specific subpackage. For example, to use the aperture photometry tools, you can import a class directly:

>>> from photutils.aperture import CircularAperture
>>> aper = CircularAperture((10, 20), r=4)

Alternatively, you can import the subpackage itself:

>>> from photutils import aperture
>>> aper = aperture.CircularAperture((10, 20), r=4)

Warning

Do not import from a subpackage’s internal modules. This is unnecessary and the internal organization of subpackages may change without notice. All public tools are available directly at the subpackage level. For example, do not import from the internal circle module within the aperture subpackage:

>>> # Do not import internal modules
>>> from photutils.aperture.circle import CircularAperture
>>> aper = CircularAperture((10, 20), r=4)

Warning

Modules, functions, classes, methods, and attributes whose names begin with a leading underscore are considered private objects and should not be imported or accessed. If a module or subpackage name begins with a leading underscore, then none of its members are public, regardless of whether they begin with a leading underscore.

Private objects are not intended for public use and may change without notice.