If sep is given, consecutive delimiters are not grouped together and are deemed to delimit empty strings (e,g, '1,,2'.split(',') returns ['1', '', '2']).
>>> doc = "/usr/share/doc/python//html"
>>> doc.split("/")
['', 'usr', 'share', 'doc', 'python', '', 'html']
The sep argument may consist of multiple characters (e.g., '1<>2<>3'.split('<>') returns ['1', '2', '3']).
Splitting an empty string with a specified separator returns [''].
If sep is not specified or None, every run of consecutive whitespaces ia regarded as a single separator, and the result will contain no empty strings at the start or end if the string has leading or trailing whitespace.
>>> mammon = "The god of the world's"
>>> mammon.rsplit()
['The', 'god', 'of', 'the', "world's"]
>>> mammon.rsplit(" ")
['The', '', '', 'god', '', '', 'of', 'the', "world's"]