DataCollection

class gdt.core.collection.DataCollection

Bases: object

A container for a collection of like data objects, such as a collection of Phaii objects. This class exposes the individual objects’ attributes, and it exposes the methods of the object class so that methods can be called on the collection as a whole. For that reason, each object in the DataCollection must be of the same type, otherwise an error is raised. The type of the collection is set by the first object inserted into the collection and the collection type is immutable thereafter.

Objects are stored in the collection in the order they are added.

The number of items in the collection can be retrieved by len() and one can iterate over the items:

[data_item for data_item in DataCollection]

In addition to the DataCollection methods, all of the individual object attributes and methods are exposed, and they become methods of the DataCollection. Note that individual object attributes become methods i.e. if you have an item attribute called item.name, then the corresponding DataCollection method would be item.name().

Attributes Summary

items	The names of the items in the DataCollection
types	The type of the objects in the DataCollection

Methods Summary

from_list(data_list[, names])	Given a list of objects and optionally a list of corresponding names, create a new DataCollection.
get_item(item_name)	Retrieve an object from the DataCollection by name
include(data_item[, name])	Insert an object into the collection.
remove(item_name)	Remove an object from the collection given the name
to_list()	Return the objects contained in the DataCollection as a list.

Attributes Documentation

items

The names of the items in the DataCollection

Type:

(list)

types

The type of the objects in the DataCollection

Type:

(str)

Methods Documentation

classmethod from_list(data_list, names=None)

Given a list of objects and optionally a list of corresponding names, create a new DataCollection.

Parameters:

• data_list (list of objects) – The list of objects to be in the collection

• names (list of str, optional) – The list of corresponding names to the objects. If not set, will try to retrieve a name from object.filename (assuming it’s a data object). If that fails, each item will be named ambiguously ‘item1’, ‘item2’, etc.

Returns

(DataCollection)

get_item(item_name)

Retrieve an object from the DataCollection by name

Parameters:

item_name (str) – The name of the item to retrieve

Returns:

(object)

include(data_item, name=None)

Insert an object into the collection. The first item inserted will set the immutable type.

Parameters:

• data_item (object) – A data object to include

• name (str, optional) – An optional corresponding name. If not set, will try to retrieve a name from object.filename (assuming it’s a data object). If that fails, each item will be named ambiguously ‘item1’, ‘item2’, etc.

remove(item_name)

Remove an object from the collection given the name

Parameters:

item_name (str) – The name of the item to remove

to_list()

Return the objects contained in the DataCollection as a list.

Returns:

(list of objects)