str.split() with separator grouping

[Skaperen]

if sep is not given when calling str.split(), it combines runs of white-space as a single separator. if sep is given, then each character is a separator and empty strings can result when there are runs of the same character.

what i am looking for (to avoid implementing this) is a split() (and rsplit() variant) that can group runs of the same specified separator string together as a single separator. i will be doing this from back to front so i will be wanting an rsplit() variant of it.

for example, calling it gsplit:

foo = '/usr///bin///bar'
bar = whatever.gsplit(foo,'/')
print(repr(bar))

Output:
[ '','usr','bin','bar']