networkx.drawing.nx_pydot.read_dot parses dot files incorrectly

[nico5300]

I tried to load the dot file of a control flow graph created by LLVM down below into a networkx graph using this code:

import networkx.drawing.nx_pydot as nxp
import networkx as nx
g = nx.read_dot("/path/to/file/cfg.dot")
print(g.nodes)

When looking at the dotfile down below one would assume three nodes being connected by two edges. But in reality one more node gets created with the label "\\n".

Steps to Reproduce

Load following dotfile with the code above and print the node list:

digraph "CFG for 'fn_1140' function" {
	label="CFG for 'fn_1140' function";

	Node0x5563aaa6daa0 [shape=record,color="#b70d28ff", style=filled, fillcolor="#b70d2870",label="{entry_fn_1140}"];
	Node0x5563aaa6daa0 -> Node0x5563aaa6f850;
	Node0x5563aaa6dc60 [shape=record,color="#b70d28ff", style=filled, fillcolor="#b70d2870",label="{exit_fn_1140}"];
	Node0x5563aaa6f850 [shape=record,color="#b70d28ff", style=filled, fillcolor="#b70d2870",label="{bb_1140}"];
	Node0x5563aaa6f850 -> Node0x5563aaa6dc60;
}

When removing the newline immediately preceeding the closing curly brace, we get the correct graph. Also when swapping the last node definition with the last edge definition.

Environment

Python version: 3.10
NetworkX version: 2.6.3
Pydot version: 1.4.2

[rossbar]

I suspect this is related to pydot/pydot#277. NetworkX has had to xfail the nx_pydot tests due to the pydot/pyparsing issues. You can try installing the older version of pyparsing in your environment, e.g.

pip install pyparsing==2.4.7
pip install pydot networkx

Though this certainly isn't a long term solution. Unfortunately I don't think there's anything NX can do unless/until this is fixed upstream.

[nico5300]

Ah I see! Thanks for the workaround :)
I'll close the issue then.