Block.vertex_attribute

Block.vertex_attribute(key, name, value=None)

Get or set an attribute of a vertex.

Parameters:
keyint

The vertex identifier.

namestr

The name of the attribute

valueobject, optional

The value of the attribute.

Returns:
object | None

The value of the attribute, or None when the function is used as a “setter”.

Raises:
KeyError

If the vertex does not exist.