使用 graphviz 更改特定节点形状 python

Question

I am currently trying to generate a graph, but I have one condition on that graph and that is that nodes with only outgoing arrows should be ellipses, the rest should have a box shape, this is what I have:

So in this case I want: 'Place Order-Importance shift-I-Obiect Typc--Customers' and 'Place Order--Quantity shift-1--Object Type--Orders' to be ellipses. The rest should be boxes.

I have tried multiple things including creating a list of specific nodes that should be that an ellipse shape, however it seems that one of the shape commands might be overruling an other one. Does anyone know how I can have my desired output?

Some info about the code:

I make a list called differences with the nodes that should have an ellips shape, the rest should be box shape.

The model object is an object that contains all the edges but comes from another previously build code which I would rather not change since I think it should be possible to it here.

An edge object of model contains a 'source' node and a 'target' node.

I hope this is clear enough.

The specific code (snippet) is here:

from graphviz import Digraph

 g = Digraph('G', filename='./output/model_' + str(mi), format='png')
 # nxg = nx.DiGraph()
 g.graph_attr.update(rankdir='BT')

 g.attr('node', shape='box')
 sources= list()
 targets = list()
 PossibleModel.MAX_DEPTH = 3

 """Let us first see what the possible inputs are"""
 for edge in model.get_edges():
    sources.append(str(edge.source))
    targets.append(str(edge.target))
    
 difference = list(set(sources) - set(targets))
 print('difference',difference)

 for edge in model.get_edges():
   edge_contained = ''
     for rule in br_rules:
         if str(edge.source) in rule or str(edge.target) in rule:
            edge_contained += rule + '\n'
     if edge_contained == '':
        g.attr('edge', color='red')
        g.edge(str(edge.source), str(edge.target),label=str(edge.weight))
        if str(edge.source) in difference:
            g.attr('node',attrs=str(edge.source),shape='ellipse')
        else:
            g.attr('node',attrs=str(edge.source), shape='box')
        g.attr('node',attrs=str(edge.target))
        
     else:
        g.attr('edge', color='blue')
        #str(round(edge.correlation, 2)))
        g.edge(str(edge.source), str(edge.target), label=edge_contained)
        if str(edge.source) in difference:
            g.attr('node',attrs=str(edge.source),shape='ellipse')
        else:
            g.attr('node',attrs=str(edge.source), shape='box')
        g.attr('node',attrs=str(edge.target), shape='box')

The Dot file code is here:

digraph G {
graph [rankdir=BT]
node [shape=box]
edge [color=red]
"Place Order--Quantity_shift-1--Object_Type--Orders" -> "Determine shipping method--Shipping Method_shift-1--Object_Type--Orders" [label=100]
node [attrs="Place Order--Quantity_shift-1--Object_Type--Orders" shape=ellipse]
node [attrs="Determine shipping method--Shipping Method_shift-1--Object_Type--Orders"]
edge [color=red]
"Place Order--Importance_shift-1--Object_Type--Customers" -> "Determine shipping method--Shipping Method_shift-1--Object_Type--Orders" [label=100]
node [attrs="Place Order--Importance_shift-1--Object_Type--Customers" shape=ellipse]
node [attrs="Determine shipping method--Shipping Method_shift-1--Object_Type--Orders"]
edge [color=red]
"Calculate Order Value--Order Value_shift-1--Object_Type--Orders" -> "Determine shipping method--Shipping Method_shift-1--Object_Type--Orders" [label=100]
node [attrs="Determine shipping method--Shipping Method_shift-1--Object_Type--Orders"]
edge [color=red]
"Place Order--Quantity_shift-1--Object_Type--Orders" -> "Calculate Order Value--Order Value_shift-1--Object_Type--Orders" [label=100]
node [attrs="Place Order--Quantity_shift-1--Object_Type--Orders" shape=ellipse]
node [attrs="Calculate Order Value--Order Value_shift-1--Object_Type--Orders"]}'

Answer 1

Here is a solution using the gvpr language ( http://www.graphviz.org/pdf/gvpr.1.pdf ). gvpr comes with the Graphviz package so it should already be present on your computer.
As a one-liner:
gvpr -c 'N{if ($.indegree==0)$.shape="ellipse";else $.shape="box";}' yourfile.gv
What it does:

• for each node
  • if there are 0 incoming edges ( indegree ) - set shape to ellipse
  • else set shape to box