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Note

This documents the development version of NetworkX. Documentation for the current release can be found here.

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networkx.classes.function.freeze¶

freeze(G)[source]¶

Modify graph to prevent further change by adding or removing nodes or edges.

Node and edge data can still be modified.

Parameters: G (graph) – A NetworkX graph

Examples

>>> G = nx.path_graph(4)
>>> G = nx.freeze(G)
>>> try:
...     G.add_edge(4, 5)
... except nx.NetworkXError as e:
...     print(str(e))
Frozen graph can't be modified

Notes

To “unfreeze” a graph you must make a copy by creating a new graph object:

>>> graph = nx.path_graph(4)
>>> frozen_graph = nx.freeze(graph)
>>> unfrozen_graph = nx.Graph(frozen_graph)
>>> nx.is_frozen(unfrozen_graph)
False