Andrei: That is a very interesting observation, thank you for pointing it out. I guess your example / argument also currently applies to whitespace separation too. For example, if we have a whitespace separated string with contents:

col1 col2 col3
a b c

x y z

then using [row.split() for row in contents.splitlines()] results in
[['col1', 'col2', 'col3'], ['a', 'b', 'c'], [], ['x', 'y', 'z']]

However if later a user appends the row:

p  q

aiming to have p, and empty cell and then q then they will actually get

[['col1', 'col2', 'col3'], ['a', 'b', 'c'], [], ['x', 'y', 'z'], ['p', 'q']]

So at least this patch results in behaviour that is consistent with how split currently works. 

Are you suggesting that this is something that could be addressed by clearer documentation or using a different flag name?