python - Pycallgraph with Spyder does not work -

I run code below verbatim (which is an official sample code):

and I get the following error:

'command' {} "must be in your path. ' 'Format (CMD) pycallgraph.exceptions.PyCallGraphException: Command "dot" must be in your path.

I'm running this program from Windows to Spider: ' C: \ MyDocs \ pleasework.py '
' C: \ MyDocs exists in sys.path

pycallgraph module using dot command Tries, which is not available in your system. You should install the dot utility that is provided by the GrafWeZ package.