Sphinx doctest fails while exactly the same for Got and Expected

Question

I got this fail report:

Document: readme
----------------
**********************************************************************
File "readme.rst", line ?, in default
Failed example:
    a
Expected:
    array(['Joe', 'Jane'],
          dtype='<U4')
Got:
    array(['Joe', 'Jane'],
          dtype='<U4')
**********************************************************************

There is a number of questions like this:

• Doctest returning failure, yet "Expected" and "Got" match perfectly

• python doctest: expected result is the same as the "got" result but the test failed

• Python doctest failed for equal "Expected" and "Got"

They all suggest looking for 'hidden' characters or spaces.

My reStructuredText looks like this:

test1:

    >>> a = np.array(['Joe', 'Jane'])
    >>> a
    array(['Joe', 'Jane'],
          dtype='<U4')

test2:

    >>> b = np.array([1,2,3])
    >>> b
    array([1, 2, 3])

test2 ran just fine.

I ran the code in a python command line and copy-pasted the result in the reStructuredtext, yet get this error. I copied the text from the fail report and pasted it back in a python string and compared with a==b (got True). I have many other examples in the same file that doctest just fine.

What can the hidden character possibly be and how do I get rid of it? What else can I do to figure where the problem is?

Is the there maybe something specific about numpy arrays?

I'd think this example is simple enough that other people must have stumbled on it...