Function write_gml

easygraph/readwrite/gml.py:662–723

Write a graph `G` in GML format to the file or file handle `path`. Parameters ---------- G : EasyGraph graph The graph to be converted to GML. path : filename or filehandle The filename or filehandle to write. Files whose names end with .gz or .bz2 will be c

(G, path, stringizer=None)

@open_file(1, mode="wb")
def write_gml(G, path, stringizer=None):
    """Write a graph `G` in GML format to the file or file handle `path`.

    Parameters
    ----------
    G : EasyGraph graph
        The graph to be converted to GML.

    path : filename or filehandle
        The filename or filehandle to write. Files whose names end with .gz or
        .bz2 will be compressed.

    stringizer : callable, optional
        A `stringizer` which converts non-int/non-float/non-dict values into
        strings. If it cannot convert a value into a string, it should raise a
        `ValueError` to indicate that. Default value: None.

    Raises
    ------
    EasyGraphError
        If `stringizer` cannot convert a value into a string, or the value to
        convert is not a string while `stringizer` is None.

    See Also
    --------
    read_gml, generate_gml
    literal_stringizer

    Notes
    -----
    Graph attributes named 'directed', 'multigraph', 'node' or
    'edge', node attributes named 'id' or 'label', edge attributes
    named 'source' or 'target' (or 'key' if `G` is a multigraph)
    are ignored because these attribute names are used to encode the graph
    structure.

    GML files are stored using a 7-bit ASCII encoding with any extended
    ASCII characters (iso8859-1) appearing as HTML character entities.
    Without specifying a `stringizer`/`destringizer`, the code is capable of
    writing `int`/`float`/`str`/`dict`/`list` data as required by the GML
    specification.  For writing other data types, and for reading data other
    than `str` you need to explicitly supply a `stringizer`/`destringizer`.

    Note that while we allow non-standard GML to be read from a file, we make
    sure to write GML format. In particular, underscores are not allowed in
    attribute names.
    For additional documentation on the GML file format, please see the
    `GML url <https://web.archive.org/web/20190207140002/http://www.fim.uni-passau.de/index.php?id=17297&L=1>`_.

    See the module docstring :mod:`easygraph.readwrite.gml` for more details.

    Examples
    --------
    >>> G = eg.path_graph(4)
    >>> eg.write_gml(G, "test.gml")

    Filenames ending in .gz or .bz2 will be compressed.