Here is the original error output:

https://gist.github.com/wjwwood/5079212

And the related thread I found:

http://sourceforge.net/projects/pyparsing/forums/forum/337293/topic/6481050

Original comment by WJWwood on 4 Mar 2013 at 1:02

I came to raise this exact issue.

Original comment by dev.yei...@gmail.com on 26 Mar 2013 at 12:00

Obvious to the initiated but not to the newbie: The workaround is to install 
pyparsing < 2.0.0 prior to installing pydot (or a package that depends on 
pydot.)

$ pip install pyparsing==1.5.7

Original comment by inactiv...@gmail.com on 26 Apr 2013 at 1:45

Thanks I forgot to post the workaround I used.

Shameless bump, in the mean time I would say that pydot version depending on 
pyparsing would help keep users from hitting this same issue.  I would be in 
favor of dropping the version dependency again after one or more of the major 
operating systems comes with Python3.x as the default version of Python. Until 
then its my opinion that we should flip this around and required the Python3 
users to get the correct version of pyparsing manually.

Original comment by WJWwood on 26 Apr 2013 at 4:46

Also came here to report this issue; but also, have a solution -- since the 
setup.py is just a python file, could one do something like this?

if python.version >= 3.0:
    install_requires = ['pyparsing', 'setuptools']
else:
    install_requires = ['pyparsing < 2.0.0', 'setuptools']

Original comment by sh...@shishnet.org on 2 Jul 2013 at 8:41

I agree that would be a good solution also, either way I know a tonne of people 
in our community are running into this problem and we have to keep pointing 
them to this issue...

Original comment by WJWwood on 2 Jul 2013 at 5:09

Have things improved since the release of pyparsing 2.0.1 is backward 
compatible to Python 2.6 and 2.7?

Original comment by ptmcg...@gmail.com on 3 Aug 2013 at 9:56

I can now install pydot against pyparsing 2.0.1, but now I get:

>>> import pydot
Couldn't import dot_parser, loading of dot files will not be possible.

Which is probably worth a new ticket here (if there isn't already one), see:

http://stackoverflow.com/questions/15951748/pydot-and-graphviz-error-couldnt-imp
ort-dot-parser-loading-of-dot-files-will

Original comment by WJWwood on 3 Aug 2013 at 6:24

in dot_patser.py:

• remove _noncomma from the 28
• add the below at line 30 of: _noncomma = "".join( [ c for c in printables if c != "," ] )

_-prefixed variables should be considered private to the module!

Original comment by grizzly.nyo on 31 Aug 2013 at 11:37

See http://stackoverflow.com/a/21462609/722624

Original comment by david.vi...@gmail.com on 30 Jan 2014 at 4:54

This is the patch i'm about to apply to the Debian package

Original comment by sandro.tosi on 11 Mar 2014 at 7:16

Attachments:

• support-pyparsing-v2.patch

Sandro, thanks for the patch.

Original comment by mar...@martindengler.com on 12 Mar 2014 at 2:03

Is there any possibility of getting a pydot release with sandro.tosi's patch?

Original comment by mar...@martindengler.com on 11 Apr 2014 at 2:52

To clarify, if you look at the last stackoverflow link, there's a fork with the 
patch applied. But yeah - this is a major issue. Bump?

Original comment by davcl...@gmail.com on 8 Aug 2014 at 6:30

bump

Original comment by asilen...@mirantis.com on 24 Feb 2015 at 4:38

Any progress here?

This fixes it for me:
pip install pydot2

import dot_parser

Traceback (most recent call last):
File "", line 1, in
File "/Library/Python/2.7/site-packages/dot_parser.py", line 23, in
from pyparsing import ( nestedExpr, Literal, CaselessLiteral, Word, Upcase, OneOrMore, ZeroOrMore,
ImportError: cannot import name _noncomma

It seems pip install pydot2 is a nice workaround.

FTR: I updated the patch (and so even the package) we use in Debian to https://anonscm.debian.org/cgit/python-modules/packages/pydot.git/tree/debian/patches/0002-support-python3.patch (which is basically https://github.com/nlhepler/pydot/ as of today)

6dff94b fixes this issue, by applying the changes suggested above, and present in nlhelper/pydot and other forks, (to not from pyparsing import _noncomma), and also the unused pyparsing.Upcase, which has been removed too from pyparsing >= 2.0.1.

Note that these changes make pydot >= 1.1.0 compatible with pyparsing >= 1.5.7.