I've done a little searching but have not found a lint check for the following:
[ 'a', 'b' 'c' ]
evaluates to ['a', 'bc'] due to implicit string concatenation, but usually it's intended to be ['a', 'b', 'c']. If it is meant to be ['a', 'bc'] it's bad style.
Guido recommends popular lint tools add a rule for this here: https://groups.google.com/forum/#!msg/python-ideas/jP1YtlyJqxs/FacZu-WK_9AJ
If this check does not exist, I would be willing to create a flake8 plugin and add it to PyCQA.