How to add and show weights on edges of a undirected graph using PyGraphviz?

Question

``` import pygraphviz as pgv A = pgv.AGraph() A.add_node('Alice') A.add_node('Emma') A.add_node('John') A.add_edge('Alice', 'Emma') A.add_edge('Alice', 'John') A.add_edge('Emma', 'John') print A.string() print "Wrote simple.dot" A.write('simple.dot') # write to simple.dot B = pgv.AGraph('simple.dot') # create a new graph from file B.layout() # layout with default (neato) B.draw('simple.png') # draw png print 'Wrote simple.png' ``` I want to add weights to the edges which should also show up on the figure.

Accepted Answer

You can add attributes to the edges when you create them:

```
A.add_edge('Alice', 'Emma', weight=5)
```

or you can set them later with:

```
edge = A.get_edge('Alice', 'Emma')
edge.attr['weight'] = 5
```

To add textual information to edges, give them a `label` attribute instead:

```
edge = A.get_edge('Alice', 'Emma')
edge.attr['label'] = '5'
```

All attributes are internally stored as strings but GraphViz interprets these as specific types; see the attribute documentation.

How to add and show weights on edges of a undirected graph using PyGraphviz?

Solution

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