pretty printing graphs

[Bengt Richter]

On 28 Jul 2003 16:30:03 -0700, mis6 at pitt.edu (Michele Simionato) wrote:

>"Scherer, Bill" <Bill.Scherer at verizonwireless.com> wrote in message news:<mailman.1059413382.3564.python-list at python.org>...
>
>Hey "dot" is great! I didn't know about it before readin your post.
>
>In a very short time I came out with the following recipe to draw
>Python inheritance hierarchies (which I post since it is pretty
>short and useful ;):
>
>
>"How to draw inheritance hierarchies via dot"
>
>import os
>
>def label(i,n):
>    if n>1: return '[label="%s"]' % (i+1)
>    return ""
>
>def dotMRO(cls):
>    "Generates the dot code for the MRO directed graph"
>    yield "digraph MRO_of_%s{\n" % cls.__name__
>    for c in cls.__mro__:
>        n=len(c.__bases__)
>        yield ' '.join(['  %s -> %s %s;' % (b.__name__,c.__name__,label(i,n))
>                         for i,b in enumerate(c.__bases__)])
>    yield '}'
>
># Example hierarchy    
>O = object
>class F(O): pass
>class E(O): pass
>class D(O): pass
>class G(O): pass
>class C(F,D,G): pass
>class B(E,D): pass
>class A(B,C): pass
>
># creates the graph
>dotcode='\n'.join(dotMRO(A)); print dotcode
>os.system('echo "%s" | dot -Tps > prova.ps' % dotcode)
>os.system('gv prova.ps&')
>
>Assuming you have "dot" and the standard Unix tools installed this 
>will generate a very nice diagram. I am open to suggestion to improve it,  
>since this is may first trial with "dot". I am quite impressed by the
>easy of use.
>
>Very nice!
>
Decided to try the tree print I did for John Hunter in pphunter.py on your class tree:
explore is just a quick-n-dirty to make the tree.

====< mrog.py >=====================
# Example hierarchy    
O = object
class F(O): pass
class E(O): pass
class D(O): pass
class G(O): pass
class C(F,D,G): pass
class B(E,D): pass
class A(B,C): pass

import pphunter
def explore(cls, tree):
    node = pphunter.Node(pphunter.TextBox(cls.__name__))
    tree.children.append(node)
    for b in cls.__bases__: explore(b, node)

root = pphunter.Node(pphunter.TextBox('root'))
explore(A, root)
print root.children[0].showInPage(20, 60)
====================================

Result:

[21:26] C:\pywk\clp>python mrog.py
                            +-+
                            |A|
                            +-+

           +-+                           +-+
           |B|                           |C|
           +-+                           +-+

     +-+          +-+         +-+        +-+        +-+
     |E|          |D|         |F|        |D|        |G|
     +-+          +-+         +-+        +-+        +-+

   +------+     +------+    +------+   +------+   +------+
   |object|     |object|    |object|   |object|   |object|
   +------+     +------+    +------+   +------+   +------+

I guess I will have to do connector lines ;-)

BTW, I found a bug in the showInPage method of pphunter.Node. It should be

--
    def showInPage(self, pageHeight=6*11, pageWidth=78):
        return '\n'.join(self.boxlines(pageHeight, pageWidth))
--
(I capitalized pageHeight and page Width) . Boo :-(
(see 'pretty printing graphs' thread).



Regards,
Bengt Richter