Class NodeView

networkx/classes/reportviews.py:118–284

A NodeView class to act as G.nodes for a NetworkX Graph Set operations act on the nodes without considering data. Iteration is over nodes. Node data can be looked up like a dict. Use NodeDataView to iterate over node data or to specify a data attribute for lookup. NodeDataView is cr

# NodeViews
class NodeView(Mapping, Set):
    """A NodeView class to act as G.nodes for a NetworkX Graph

    Set operations act on the nodes without considering data.
    Iteration is over nodes. Node data can be looked up like a dict.
    Use NodeDataView to iterate over node data or to specify a data
    attribute for lookup. NodeDataView is created by calling the NodeView.

    Parameters
    ----------
    graph : NetworkX graph-like class

    Examples
    --------
    >>> G = nx.path_graph(3)
    >>> NV = G.nodes()
    >>> 2 in NV
    True
    >>> for n in NV:
    ...     print(n)
    0
    1
    2
    >>> assert NV & {1, 2, 3} == {1, 2}

    >>> G.add_node(2, color="blue")
    >>> NV[2]
    {'color': 'blue'}
    >>> G.add_node(8, color="red")
    >>> NDV = G.nodes(data=True)
    >>> (2, NV[2]) in NDV
    True
    >>> for n, dd in NDV:
    ...     print((n, dd.get("color", "aqua")))
    (0, 'aqua')
    (1, 'aqua')
    (2, 'blue')
    (8, 'red')
    >>> NDV[2] == NV[2]
    True

    >>> NVdata = G.nodes(data="color", default="aqua")
    >>> (2, NVdata[2]) in NVdata
    True
    >>> for n, dd in NVdata:
    ...     print((n, dd))
    (0, 'aqua')
    (1, 'aqua')
    (2, 'blue')
    (8, 'red')
    >>> NVdata[2] == NV[2]  # NVdata gets 'color', NV gets datadict
    False
    """

    __slots__ = ("_nodes",)

    def __getstate__(self):
        return {"_nodes": self._nodes}