Subgraph

Specify a subgraph in pygraphviz.

strict graph "" {
        subgraph s1 {
                graph [rank=same];
                4 -- 6;
                5;
        }
        1 -- 2;
        1 -- 3;
        2 -- 3;
        3 -- 4;
        3 -- 5;
        3 -- 6;
}

/usr/lib64/python3.11/site-packages/pygraphviz/agraph.py:1403: RuntimeWarning: Error: fontconfig: Couldn't find font.
Error: fontconfig: Couldn't find font.
Error: fontconfig: Couldn't find font.
Error: fontconfig: Couldn't find font.
Error: fontconfig: Couldn't find font.
Error: fontconfig: Couldn't find font.

  warnings.warn(b"".join(errors).decode(self.encoding), RuntimeWarning)

import pygraphviz as pgv

A = pgv.AGraph()
# add some edges
A.add_edge(1, 2)
A.add_edge(2, 3)
A.add_edge(1, 3)
A.add_edge(3, 4)
A.add_edge(3, 5)
A.add_edge(3, 6)
A.add_edge(4, 6)
# make a subgraph with rank='same'
B = A.add_subgraph([4, 5, 6], name="s1", rank="same")
B.graph_attr["rank"] = "same"
print(A.string())  # print dot file to standard output
A.draw("subgraph.png", prog="neato")