GML

Node ids

A graph loaded from GML keeps each node’s id as the external id of its vertex, as in MØD. The vertices themselves are renumbered, since a graph is stored in canonical order, so look a vertex up by the id it was given with molfoundry.Graph.getVertexFromExternalId():

g = mf.Graph.fromGMLString("""graph [
    node [ id 10 label "O" ] node [ id 20 label "H" ] node [ id 30 label "C" ]
    edge [ source 10 target 20 label "-" ] edge [ source 10 target 30 label "-" ]
]""")
v = g.getVertexFromExternalId(30)
print(v.id, v.stringLabel, v.externalId)

0 C 30

Graphs a derivation creates have no external ids. Depictions omit them unless molfoundry.GraphPrinter.withExternalId is set:

printer = mf.GraphPrinter()
printer.withExternalId = True
g.print(printer)

g_{0}