Hi Rajiv, thanks for the report, but this is already possible by default. I will use the factorial example from https://docs.python.org/3.5/library/doctest.html to demonstrate it:

    $ python -m doctest example.py
    $ echo $?
    0

Now change the following line

    >>> [factorial(n) for n in range(6)]

to

    >>> [factorial(n) for n in range(5)]

and run the script again:

    $ python -m doctest example.py
    [...]
    ***Test Failed*** 1 failures.
    $ echo $?
    1