Function empty_graph

networkx/generators/classic.py:566–660

Returns the empty graph with n nodes and zero edges. .. plot:: >>> nx.draw(nx.empty_graph(5)) Parameters ---------- n : int or iterable container of nodes (default = 0) If n is an integer, nodes are from `range(n)`. If n is a container of nodes, those nodes

(n=0, create_using=None, default=Graph)

@nx._dispatchable(graphs=None, returns_graph=True)
@nodes_or_number(0)
def empty_graph(n=0, create_using=None, default=Graph):
    """Returns the empty graph with n nodes and zero edges.

    .. plot::

        >>> nx.draw(nx.empty_graph(5))

    Parameters
    ----------
    n : int or iterable container of nodes (default = 0)
        If n is an integer, nodes are from `range(n)`.
        If n is a container of nodes, those nodes appear in the graph.
    create_using : Graph Instance, Constructor or None
        Indicator of type of graph to return.
        If a Graph-type instance, then clear and use it.
        If None, use the `default` constructor.
        If a constructor, call it to create an empty graph.
    default : Graph constructor (optional, default = nx.Graph)
        The constructor to use if create_using is None.
        If None, then nx.Graph is used.
        This is used when passing an unknown `create_using` value
        through your home-grown function to `empty_graph` and
        you want a default constructor other than nx.Graph.

    Examples
    --------
    >>> G = nx.empty_graph(10)
    >>> G.number_of_nodes()
    10
    >>> G.number_of_edges()
    0
    >>> G = nx.empty_graph("ABC")
    >>> G.number_of_nodes()
    3
    >>> sorted(G)
    ['A', 'B', 'C']

    Notes
    -----
    The variable create_using should be a Graph Constructor or a
    "graph"-like object. Constructors, e.g. `nx.Graph` or `nx.MultiGraph`
    will be used to create the returned graph. "graph"-like objects
    will be cleared (nodes and edges will be removed) and refitted as
    an empty "graph" with nodes specified in n. This capability
    is useful for specifying the class-nature of the resulting empty
    "graph" (i.e. Graph, DiGraph, MyWeirdGraphClass, etc.).

    The variable create_using has three main uses:
    Firstly, the variable create_using can be used to create an
    empty digraph, multigraph, etc.  For example,

    >>> n = 10
    >>> G = nx.empty_graph(n, create_using=nx.DiGraph)

    will create an empty digraph on n nodes.

    Secondly, one can pass an existing graph (digraph, multigraph,
    etc.) via create_using. For example, if G is an existing graph