pydot and graphviz error: Couldn't import dot_parser, loading of dot files will not be possible

Question

When I run a very simple code with pydot

import pydot
graph = pydot.Dot(graph_type=\'graph\')

for i in range(3):

  edge = pydot.Edge(\"king\", \"lord%d\" %         


        

Answer 1

pydot used a private module variable (_noncomma) from pyparsing. The below diff fixes it to use for pyparsing 2.0.1:

diff --git a/dot_parser.py b/dot_parser.py
index dedd61a..138d152 100644
--- a/dot_parser.py
+++ b/dot_parser.py
@@ -25,8 +25,9 @@ from pyparsing import __version__ as pyparsing_version
 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: