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


read_graphml(path, node_type=<class 'str'>, edge_key_type=<class 'int'>, force_multigraph=False)[source]

Read graph in GraphML format from path.

  • path (file or string) – File or filename to write. Filenames ending in .gz or .bz2 will be compressed.

  • node_type (Python type (default: str)) – Convert node ids to this type

  • edge_key_type (Python type (default: int)) – Convert graphml edge ids to this type. Multigraphs use id as edge key. Non-multigraphs add to edge attribute dict with name “id”.

  • force_multigraph (bool (default: False)) – If True, return a multigraph with edge keys. If False (the default) return a multigraph when multiedges are in the graph.


graph – If parallel edges are present or force_multigraph=True then a MultiGraph or MultiDiGraph is returned. Otherwise a Graph/DiGraph. The returned graph is directed if the file indicates it should be.

Return type

NetworkX graph


Default node and edge attributes are not propagated to each node and edge. They can be obtained from G.graph and applied to node and edge attributes if desired using something like this:

>>> default_color = G.graph["node_default"]["color"]  
>>> for node, data in G.nodes(data=True):  
...     if "color" not in data:
...         data["color"] = default_color
>>> default_color = G.graph["edge_default"]["color"]  
>>> for u, v, data in G.edges(data=True):  
...     if "color" not in data:
...         data["color"] = default_color

This implementation does not support mixed graphs (directed and unidirected edges together), hypergraphs, nested graphs, or ports.

For multigraphs the GraphML edge “id” will be used as the edge key. If not specified then they “key” attribute will be used. If there is no “key” attribute a default NetworkX multigraph edge key will be provided.

Files with the yEd “yfiles” extension will can be read but the graphics information is discarded.

yEd compressed files (“file.graphmlz” extension) can be read by renaming the file to “file.graphml.gz”.