A little utility to convert a textual description of classes to a UML diagram (in dot format).

makeuml.py

#!/usr/bin/python

# This code is public domain, share and enjoy.

import sys, re

rEdge = re.compile(r'(\w+)\s+([\w.*]*)\s*(--|->|<-|<->)\s*([\w.*]*)\s+(\w+)\s*')
rName = re.compile(r'\w+')

arrows = {
'--': ('none','none'),
'<-': ('open', 'none'),
'->': ('none', 'open'),
'<->': ('open', 'open')
}


def format(props):
  rval = '['
  for k,v in props.items():
    rval += "%s=\"%s\" " % (k,v)
  rval += ']'
  return rval
  
def emit(current,fields):
  if current:
    label = ""
    for field in fields:
      label += field+"\l"
    label = "{%s|%s}" % (current, label)
    print current, format({'label': label})

if len(sys.argv) < 2:
  print sys.argv[0], "converts simple-uml to dot graphs"
  print "syntax:"
  print """
Foo -> Bar
Bar * -- 1 Baz
Baz -- Fred
Baz --* Foo
Fred -> 1 Joe

Joe
- name : String
- potato : boolean

Fred
- name : String
- children : int

"""
  sys.exit(1)


print "Graph G {\n  node [ shape=\"record\" label=\"{\\N}\"]\n"
  
current = None
fields = []

for line in open(sys.argv[1]):
  if line.startswith("#"):
    continue
  
  line = line.strip()
  m = rEdge.match(line)
  if m:
    (left, leftLabel, arrow, rightLabel, right) = m.groups()
    
    (arrowtail,arrowhead) = arrows[arrow]
    props = {'arrowhead':arrowhead,'arrowtail':arrowtail}
    if leftLabel:
      props['taillabel'] = leftLabel
    if rightLabel:
      props['headlabel'] = rightLabel
      
    print "%s -- %s %s\n" % (left, right, format(props))
    continue
  
  m = rName.match(line)
  if m:
    emit(current,fields)
    current = m.group(0)
    fields = []
    continue
    
  if line.startswith("- "):
    fields.append(line)

emit(current,fields)
    
print "}\n"