taipy.core.DataNode

Bases: _Entity, _Labeled

Reference to a dataset.

A Data Node is an abstract class that holds metadata related to the dataset it refers to. In particular, a data node holds the name, the scope, the owner identifier, the last edit date, and some additional properties of the data.
A Data Node also contains information and methods needed to access the dataset. This information depends on the type of storage, and it is held by subclasses (such as SQL Data Node, CSV Data Node, ...).

Note

It is recommended not to instantiate subclasses of DataNode directly.

Attributes:

Name	Type	Description
config_id	str	Identifier of the data node configuration. It must be a valid Python identifier.
scope	Scope	The scope of this data node.
id	str	The unique identifier of this data node.
name	str	A user-readable name of this data node.
owner_id	str	The identifier of the owner (sequence_id, scenario_id, cycle_id) or None.
parent_ids	Optional[Set[str]]	The set of identifiers of the parent tasks.
last_edit_date	datetime	The date and time of the last modification.
edits	List[Edit]	The list of Edits (an alias for dict) containing metadata about each data edition including but not limited to timestamp, comments, job_id: timestamp: The time instant of the writing comments: Representation of a free text to explain or comment on a data change job_id: Only populated when the data node is written by a task execution and corresponds to the job's id. Additional metadata related to the edition made to the data node can also be provided in Edits.
version	str	The string indicates the application version of the data node to instantiate. If not provided, the current version is used.
validity_period	Optional[timedelta]	The duration implemented as a timedelta since the last edit date for which the data node can be considered up-to-date. Once the validity period has passed, the data node is considered stale and relevant tasks will run even if they are skippable (see the Task management page for more details). If validity_period is set to None, the data node is always up-to-date.
edit_in_progress	bool	True if the data node is locked for modification. False otherwise.
editor_id	Optional[str]	The identifier of the user who is currently editing the data node.
editor_expiration_date	Optional[datetime]	The expiration date of the editor lock.
kwargs	Optional[datetime]	A dictionary of additional properties.

cacheable property writable

Deprecated. Use skippable attribute of a Task instead.

edits property

Get all Edits of this data node.

expiration_date: datetime property

Datetime instant of the expiration date of this data node.

is_ready_for_reading: bool property

Indicate if this data node is ready for reading.

Returns:

Type	Description
bool	False if the data is locked for modification or if the data has never been written. True otherwise.

is_up_to_date: bool property

Indicate if this data node is up-to-date.

Returns:

Type	Description
bool	False if a preceding data node has been updated before the selected data node
bool	or the selected data is invalid.
bool	True otherwise.

is_valid: bool property

Indicate if this data node is valid.

Returns:

Type	Description
bool	False if the data ever been written or the expiration date has passed.
bool	True otherwise.

job_ids property

List of the jobs having edited this data node.

parent_ids property

List of parent ids of this data node.

properties property

Dictionary of custom properties.

append(data, job_id=None, **kwargs)

Append some data to this data node.

Parameters:

Name	Type	Description	Default
data	Any	The data to write to this data node.	required
job_id	JobId	An optional identifier of the writer.	None
**kwargs	dict[str, any]	Extra information to attach to the edit document corresponding to this write.	{}

filter(operators, join_operator=JoinOperator.AND)

Read and filter the data referenced by this data node.

The data is filtered by the provided list of 3-tuples (key, value, Operator).

If multiple filter operators are provided, filtered data will be joined based on the join operator (AND or OR).

Parameters:

Name	Type	Description	Default
operators	Union[List[Tuple], Tuple]	A 3-element tuple or a list of 3-element tuples, each is in the form of (key, value, Operator).	required
join_operator	JoinOperator	The operator used to join the multiple filter 3-tuples.	AND

get_label()

Returns the data node simple label prefixed by its owner label.

Returns:

Type	Description
str	The label of the data node as a string.

get_last_edit()

Get last Edit of this data node.

Returns:

Type	Description
Optional[Edit]	None if there has been no Edit on this data node.

get_parents()

Get all parents of this data node.

get_simple_label()

Returns the data node simple label.

Returns:

Type	Description
str	The simple label of the data node as a string.

lock_edit(editor_id=None)

Lock the data node modification.

Note

The data node can be unlocked with the method unlock_edit().

Parameters:

Name	Type	Description	Default
editor_id	Optional[str]	The editor's identifier.	None

read()

Read the data referenced by this data node.

Returns:

Type	Description
Any	The data referenced by this data node. None if the data has not been written yet.

read_or_raise()

Read the data referenced by this data node.

Returns:

Type	Description
Any	The data referenced by this data node.

Raises:

Type	Description
NoData	If the data has not been written yet.

track_edit(**options)

Creates and adds a new entry in the edits attribute without writing the data.

Parameters:

Name	Type	Description	Default
options	dict[str, any	track timestamp, comments, job_id. The others are user-custom, users can use options to attach any information to an external edit of a data node.	{}

unlock_edit(editor_id=None)

Unlocks the data node modification.

Note

The data node can be locked with the method lock_edit().

Parameters:

Name	Type	Description	Default
editor_id	Optional[str]	The editor's identifier.	None

write(data, job_id=None, **kwargs)

Write some data to this data node.

Parameters:

Name	Type	Description	Default
data	Any	The data to write to this data node.	required
job_id	JobId	An optional identifier of the writer.	None
**kwargs	dict[str, any]	Extra information to attach to the edit document corresponding to this write.	{}