--- dot_parser.py
+++ dot_parser.py
@@ -25,8 +25,9 @@
 from pyparsing import ( nestedExpr, Literal, CaselessLiteral, Word, Upcase, OneOrMore, ZeroOrMore,
     Forward, NotAny, delimitedList, oneOf, Group, Optional, Combine, alphas, nums,
     restOfLine, cStyleComment, nums, alphanums, printables, empty, quotedString,
-    ParseException, ParseResults, CharsNotIn, _noncomma, dblQuotedString, QuotedString, ParserElement )
+    ParseException, ParseResults, CharsNotIn, dblQuotedString, QuotedString, ParserElement )
 
+_noncomma = "".join( [ c for c in printables if c != "," ] )
 
 class P_AttrList: