DifferentialAttribute#

class astropy.coordinates.DifferentialAttribute(default=None, allowed_classes=None, secondary_attribute='', **kwargs)[source]#

Bases: Attribute

A frame attribute which is a differential instance.

The optional allowed_classes argument allows specifying a restricted set of valid differential classes to check the input against. Otherwise, any BaseDifferential subclass instance is valid.

Parameters:
defaultobject

Default value for the attribute if not provided

allowed_classestuple, optional

A list of allowed differential classes for this attribute to have.

secondary_attributestr

Name of a secondary instance attribute which supplies the value if default is None and no value was supplied during initialization.

docstr

Description of the frame attribute for help and documentation

Methods Summary

convert_input(value)

Checks that the input is a differential object and is one of the allowed class types.

Methods Documentation

convert_input(value)[source]#

Checks that the input is a differential object and is one of the allowed class types.

Parameters:
valueobject

Input value.

Returns:
out, convertedcorrectly-typed object, bool

Tuple consisting of the correctly-typed object and a boolean which indicates if conversion was actually performed.

Raises:
ValueError

If the input is not valid for this attribute.