http://docs.python.org/py3k/library/stdtypes.html#str.join str.join(iterable)ΒΆ Return a string which is the concatenation of the strings in the iterable iterable. A TypeError will be raised if there are any non-string values in seq, including bytes objects. The separator between elements is the string providing this method. "non-string values in seq" -> "non-string values in iterable"
I see the two as really one issue -- minor corrections to the string section of stdtype.rst -- that py.user happened to have filed as two. But I could have left out the closes and done at least one explicitly. Or I could have closed this and said I was consolidating with #13754. Thanks for pointing out the typo.