primitives.py 文件源码

def add_node(graph, node_id, attrs=None):
    """Add a node to a graph.

    Parameters
    ----------
    graph : networkx.(Di)Graph
    node_id : hashable
        Prefix that is prepended to the new unique name.
    attrs : dict, optional
        Node attributes.

    Raises
    -------
    regraph.exceptions.GraphError
        Raises an error if node already exists in the graph.
    """
    new_attrs = deepcopy(attrs)
    if new_attrs is None:
        new_attrs = dict()
    if node_id not in graph.nodes():
        graph.add_node(node_id)
        normalize_attrs(new_attrs)
        graph.node[node_id] = new_attrs
    else:
        raise GraphError("Node '%s' already exists!" % node_id)