Node#

class Node(incoming_node_data=None, degree=None, **attr)#

Bases: ABC

Abstract node that holds incident endpoints and attributes.

Endpoints are stored in CCW order in _inc; individual subclasses (e.g., Crossing, Vertex) may impose constraints on length/meaning.

Parameters:

  • incoming_node_data (Sequence[Any] | None)

  • degree (int | None)

  • attr (dict[str, Any])

attr#

Node attributes (e.g., color, weight).

Type:

dict[str, Any]

_inc#

Incident endpoints in CCW order (endpoint objects).

Type:

list[Any]

__init__(incoming_node_data=None, degree=None, **attr)#

Initialize a node with optional incident endpoints and attributes.

Parameters:

  • incoming_node_data (Sequence[Any] | None) – Existing sequence of incident endpoints; if shorter than degree, it will be padded with None.

  • degree (int | None) – Desired degree (len of incident endpoints). If omitted, inferred from incoming_node_data (or 0 if not provided).

  • **attr (Any) – Node attributes to set.

Raises:

ValueError – If incoming_node_data is longer than degree.

Return type:

None

Methods

__init__([incoming_node_data, degree])

Initialize a node with optional incident endpoints and attributes.

append(item)

Append an endpoint at the end.

degree()

Return the node degree (number of incident endpoints).

Attributes

attr

attr: dict[str, Any]#
append(item)#

Append an endpoint at the end.

Parameters:

item (Any) – Endpoint to append.

Return type:

None

degree()#

Return the node degree (number of incident endpoints).

Returns:

int – Degree.

Return type:

int