how to resolve AttributeError: module 'graphviz.backend' has no attribute 'ENCODING'

Question

I am not sure why I get an AttributeError: module 'graphviz.backend' has no attribute 'ENCODING' when I tried to export regression tree to graphviz. I tried re-installing graphviz and sklearn but it doesn't solve the problem. Appreciate any advice on this.

---

AttributeError                            Traceback (most recent call last)
<ipython-input-4-9d9e0becf9b6> in <module>
      3 # graphviz is the drawing tool
      4 from sklearn.tree import export_graphviz
----> 5 import graphviz
      6 dot_data = export_graphviz(
      7     model,

C:\ProgramData\Anaconda3\lib\site-packages\graphviz\__init__.py in <module>
     25 """
     26 
---> 27 from .dot import Graph, Digraph
     28 from .files import Source
     29 from .lang import escape, nohtml

C:\ProgramData\Anaconda3\lib\site-packages\graphviz\dot.py in <module>
     30 
     31 from . import backend
---> 32 from . import files
     33 from . import lang
     34 

C:\ProgramData\Anaconda3\lib\site-packages\graphviz\files.py in <module>
     20 
     21 
---> 22 class Base(object):
     23 
     24     _engine = 'dot'

C:\ProgramData\Anaconda3\lib\site-packages\graphviz\files.py in Base()
     26     _format = 'pdf'
     27 
---> 28     _encoding = backend.ENCODING
     29 
     30     @property

AttributeError: module 'graphviz.backend' has no attribute 'ENCODING'

Answer 1

I had a similar issue when using pipdeptree. It would seem that there was a very recent change to graphviz, intended to obfuscate its internals. Quoting the module author's reply in issue #149 (a similar issue with backend.FORMATS):

Submodules of graphviz are not part of the public API (cf. https://graphviz.readthedocs.io/en/stable/api.html). Please stick to the documented interface and use graphviz.FORMATS, see https://graphviz.readthedocs.io/en/stable/api.html#graphviz.FORMATS).

In the short term, you could downgrade your graphviz module… it looks like 0.18 was the last tag before the submodules were made opaque.

Moving forward, you may wish to create an issue and/or pull request against the sklearn-pandas repository, to replace graphviz.backend.FORMATS with graphviz.FORMATS, or even just cap its graphviz dependency at 0.18.

Answer 2

I had the same issue and I am very new to Python/conda world, so this might help newbies like me...

I downloaded graphviz 0.19.1 from: https://pypi.org/project/graphviz/#files

Source Distribution: graphviz-0.19.1.zip (247.8 kB view hashes) download link

and replaced graphviz folder with this version in "C:\Users\Nino\anaconda3\Lib\site-packages" (will be different for you) and rename it so that name is again graphviz.

"C:\Users\Nino\anaconda3\Lib\site-packages\graphviz"

Answer 3

I had the same error with python-graphviz==0.16. OP did not include a version number, but it looks like the line numbers in the traceback match with v0.16.

Note that the traceback shows the error to be inside the python-graphviz package, so it's more likely that it's an issue with a dependency.

With python-graphviz==0.19 I don't get the import error.

On a side note: Versions shown by conda list or pip list can be misleading. In case of doubt check the content of the __init__.py.

Answer 4

I solved this issue in a different way:

1. Open graphviz file on my PC through following path (Path may differ) "C:\Users\Anoop\anaconda3\Lib\site-packages\graphviz\backend"
2. Copy the encoding.py file from here
3. Paste this file in the backend "C:\Users\Anoop\anaconda3\Lib\site-packages\graphviz\backend"
4. Problem solved

Answer 5

In my case, it seems that the class Base in the "C:\ProgramData\Anaconda3\lib\site-packages\graphviz\files.py" takes the 'backend folder' instead of the 'backend.py' on init.

quick solve: go to "C:\ProgramData\Anaconda3\lib\site-packages\graphviz" and rename the 'backend folder' to something else.

PS: since I didn't check the whole code, it may then cause another dependency problem.