API Reference

List of classes and functions available in the networkx_gdf module.

class GDF

Implements read_gdf() and write_gdf() methods for GDF (Graph Data Format) files.

GDF is a compact file format originally implemented by GUESS. Although the software itself is not anymore maintained, the format is still supported by active open-source projects such as Gephi. It is based on a tabular text format, and is defined by the simple following rules:

  • A first line starting with nodedef>name VARCHAR defines the node table.

  • Each subsequent line contains a node name and its attributes separated by commas.

  • A second line starting with edgedef>node1 VARCHAR,node2 VARCHAR defines the edge table.

  • Each subsequent line contains an edge and its attributes separated by commas.

The following object types are supported by the format: VARCHAR, INT, LONG, FLOAT, DOUBLE, and BOOLEAN. The format also supports single and double quotes as text delimiters.

File example

The example below displays a simple GDF file with two nodes (\(A\), \(B\)) and one edge. Note that nodes here do not have any attributes, so the node table after the first line may be left empty:

nodedef>name VARCHAR
edgedef>node1 VARCHAR,node2 VARCHAR
A,B

A special property named directed can be added to the edge table to specify directed (True) or undirected (False) edges. If not found, the graph will be considered as undirected by default.

See also

  • The GUESS Wiki (archived) for the official GDF format documentation.

  • The Gephi Wiki for more information and examples using the format.

Code example

The following code creates the graph above, writes it to a GDF file, and reads it afterwards:

>>> import networkx as nx
>>> from networkx_gdf import read_gdf, write_gdf
>>>
>>> G = nx.Graph()
>>> G.add_edge("A", "B")
>>>
>>> write_gdf(G, "graph.gdf")
>>> read_gdf("graph.gdf")

<networkx.classes.graph.Graph object at 0x7f3b9c7b2a60>

Both methods are static and do not require instantiation as an object if the class is inherited:

>>> from networkx_gdf import GDF
>>>
>>> class MyClass(GDF):
>>>     ...
>>>
>>> G = MyClass.read_gdf("graph.gdf")
>>> MyClass.write_gdf(G, "graph.gdf")

Additional parameters are available for both methods and described in their documentation.

read_gdf(file: str | BufferedReader | BytesIO | StringIO | TextIOWrapper, directed: bool | None = None, multigraph: bool | None = None, weighted: bool | None = True, node_attr: list | bool | None = True, edge_attr: list | bool | None = True, encoding: str = 'utf-8', errors: str = 'strict') → Graph

Returns a NetworkX graph object from file path or object.

Parameters:

  • file (object) – File object or string containing path to GDF file.

  • directed (bool | None) –

    Consider edges as directed or undirected. Optional. Default is None.

    • If None, decides based on 'directed' edge attribute in file, if it exists. In case it does not exist, the graph will be considered as undirected.

    • If True, returns a DiGraph or MultiDiGraph object.

    • If False, returns a Graph or MultiGraph object.

  • multigraph (bool | None) –

    Consider multiple edges among pairs of nodes. Optional. Default is None.

    • If None, decides based on number of edges among node pairs. In case of multiple edges among the same node pairs, the graph will be considered as a multigraph, preserving dynamic edge-level attributes.

    • If True, returns a MultiGraph or MultiDiGraph object.

    • If False, sums edge weights and returns a Graph or DiGraph object.

  • weighted (bool | None) – Consider edge weights. Optional. Default is True. Only applicable if multigraph is manually set as False.

  • node_attr (list | bool | None) –

    Accepts a list or bool. Optional. Default is True.

    • If a list, only the specified attributes will be considered.

    • If True, all node attributes will be considered.

    • If False, no node attributes will be considered.

  • edge_attr (list | bool | None) –

    Accepts a list or bool. Optional. Default is True.

    • If a list, only the specified attributes will be considered.

    • If True, all edge attributes will be considered.

    • If False, no edge attributes will be considered.

  • encoding (str) – The encoding of the file. Default is 'utf-8'. For a list of possible values, see Python documentation: Standard Encodings.

  • errors (str) – The error handling scheme. Default is 'strict'. For a list of possible values, see Python documentation: Error Handlers.

Return type:

Graph

write_gdf(G: Graph, file: str | BufferedWriter | BytesIO | StringIO | TextIOWrapper | None = None, node_attr: list | bool | None = True, edge_attr: list | bool | None = True, encoding: str = 'utf-8', errors: str = 'strict') → str | None

Writes a NetworkX graph object to file path or object.

Parameters:

  • G (Graph) – NetworkX graph object.

  • file (object) – File object or string containing path to GDF file. Optional. If None (default), returns content as string.

  • node_attr (list | bool | None) –

    Accepts a list or bool. Optional. Default is True.

    • If a list, only the specified attributes will be considered.

    • If True, all node attributes will be considered.

    • If False, no node attributes will be considered.

  • edge_attr (list | bool | None) –

    Accepts a list or bool. Optional. Default is True.

    • If a list, only the specified attributes will be considered.

    • If True, all edge attributes will be considered.

    • If False, no edge attributes will be considered.

  • encoding (str) – The encoding of the file. Default is 'utf-8'. For a list of possible values, see Python documentation: Standard Encodings.

  • errors (str) – The error handling scheme. Default is 'strict'. For a list of possible values, see Python documentation: Error Handlers.

Return type:

str | None