Problem: after installing graphviz, it runs normally on the command line (Python runs normally, PDF can be output normally, pop up jump to view graphics), but documents cannot be output normally on pychart and notbook.

And an error will appear in pychar:

ExecutableNotFound: failed to execute [‘dot’], make sure the Graphviz executables are on your systems’ PATH

Solution:

Add the following two new variables to the system environment variable:

GRAPHVIZ_ DOT

GRAPHVIZ_ INSTALL_ DIR

The values are bot.exe address and graphviz root directory respectively