recurse into the subdirectories whose names remain in *dirnames*; this can be
used to prune the search, impose a specific order of visiting, or even to inform
:func:`walk` about directories the caller creates or renames before it resumes
- :func:`walk` again. Modifying *dirnames* when *topdown* is ``False`` is
- ineffective, because in bottom-up mode the directories in *dirnames* are
- generated before *dirpath* itself is generated.
+ :func:`walk` again. Modifying *dirnames* when *topdown* is ``False`` has
+ no effect on the behavior of the walk, because in bottom-up mode the directories
+ in *dirnames* are generated before *dirpath* itself is generated.
By default, errors from the :func:`listdir` call are ignored. If optional
argument *onerror* is specified, it should be a function; it will be called with