I first tried to put the following

# FIXME remove next 3 lines once 1.14 is minimum NumPy requirement
# and fix printing doctests to use new format.
from distutils.version import LooseVersion
if LooseVersion(np.__version__) >  LooseVersion("1.13.3"):
    np.set_printoptions(legacy="1.13")

after every

import numpy as np

But decided that

try:
    np.set_printoptions(legacy="1.13")
except TypeError:
    pass

was a cleaner solution.

Unfortunately, I am still getting errors. I believe these errors are not related to the changes in how NumPy prints arrays, but are due to changes between pydot 1.2.3 and pydot 1.2.4. If that seems correct, I would like to merge this and then fix the pydot 1.2.4 issue. I haven't looked into what it takes to fix the 1.2.4 (vs. 1.2.3 of pydot).

@dschult Any thoughts about this?

This PR allowed all tests to pass for many days. But now it has changed again so that the error shows when the documentation build process tests the doctests. In Travis it is the first config that produces the error in e.g. #2816 . Not sure why the legacy print options would not work in this environment.