Thank you for your report and for the PR, but I think you misunderstood documentation:

    Using square brackets, separating items with commas: [a], [a, b, c]

The comma is used to show two different lists: a list with one item ``[a]`` *and* a list with three items ``[a, b, c]``, not a tuple with two lists ``[a], [a, b, c]`` (In Python, both ``(1,)`` and ``1,`` create a tuple)

Perhaps this is what the YCMove meant?

>>> a = [1], [2, 3, 4]
>>> a
([1], [2, 3, 4])
>>>

That's why I mentioned ``[a], [a, b, c]`` in my earlier message.

Yes, the markup (and therefore how the code is displayed in the docs) clearly indicates that the , between the lists is not part of the python syntax being discussed.

Yes, what Cheryl Sabella says is what I was misled to. 

Took me a while to understand that ``[a]``, ``[a, b, c]`` is not ``[a], [a, b, c]``, how about replace comma to "or" for more clarity? just like it used in [tuple documention](https://github.com/python/cpython/blob/master/Doc/library/stdtypes.rst#tuples)

Here is my rephrased version, and I add one more example of comma separated lists in tuple according to R. David Murray.