[Python-Dev] random.jumpback?

[Skip Montanaro]

I was adding __all__ to the random module and I noticed this very unpythonic
example in the module docstring:

    >>> g = Random(42)  # arbitrary
    >>> g.random()
    0.25420336316883324
    >>> g.jumpahead(6953607871644L - 1) # move *back* one
    >>> g.random()
    0.25420336316883324

Presuming backing up the seed is a reasonable thing to do (I haven't got
much experience with random numbers), why doesn't the Random class have a
jumpback method instead of forcing the user to know the magic number to use
with jumpahead?

    def jumpback(self, n):
        return self.jumpahead(6953607871644L - n)

Skip