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.