Graphviz's executables are not found (Python 3.4)

Question

I am running Python3.4 on Windows 7. I am trying to use the Python interface for graphviz. This is a script I intend to run:

from graphviz import Digraph import pydotplus  dot = Digraph(comment='The Round Table')  dot.node('A', 'King Arthur') dot.node('B', 'Sir Bedevere the Wise') dot.node('L', 'Sir Lancelot the Brave') dot.edges(['AB', 'AL']) dot.edge('B', 'L', constraint='false')  print(dot.source) dot.render('test-output/round-table.gv', view=True) 

I get the following error at runtime:

RuntimeError: failed to execute ['dot', '-Tpdf', '-O', 'test-output/round-table.gv'], make sure the Graphviz executables are on your systems' path 

Now I am sure I have properly installed the correct dependencies. I first tried to set the correct environment variables. The graphviz executables are located at C:\Program Files (x86)\Graphviz2.37\bin so I went to the Environment Variables section. There are two sections there: User Variables and System Variables. Under System Variables I clicked on Path and then clicked Edit and added ;C:\Program Files (x86)\Graphviz2.37\bin to the end of the string and saved. This didn't clear the error.

Then, following the answer given here I uninstalled pydot (actually I use pydotplus here) and re-installed it again, but still no success.

I have been trying for hours to fix this and the whole PATH variable thing is just confusing and frustrating.

Answer 1

I also had this problem on Ubuntu 16.04.

Fixed by running sudo apt-get install graphviz in addition to the pip install I had already performed.

Answer 2

In my case (Win10, Anaconda3, Jupyter notebook) after "conda install graphviz" I have to add to the PATH: C:\Users\username\Anaconda3\Library\bin\graphviz

To modify PATH goto Control Panel > System and Security > System > Advanced System Settings > Environment Variables > Path > Edit > New