On Thu, Oct 28, 2021 at 4:34 AM Christman, Roger Graydon <d...@psu.edu> wrote: > Do you put special code in next_couple() to recognize that the provided > arguments > are actually the first couple so it can return those unmodified, but then > require its > own mental note not to give you an infinite loop forever returning that first > couple? > > Do you have to define a special case such as (a,b) = (0,0) or (None,None) to > tell > next_couple that you really want the first one? That seems a little > counter-intuitive > to have something named "next" need a special input to mean "first",
In some cases, there is a very real special startup value (a seed). For instance, if we're calculating something relating to the Mandelbrot set: # The point we're working with c = (0.25 + 0.125j) # Always start here z = (0 + 0j) # or just 0 while abs(z := z*z+c) < 2: ... Though in this case, you don't look for a next_couple, you look for a single next value, and the other value is constant. But it all depends on the exact process being done, which is why I've been asking for real examples. ChrisA -- https://mail.python.org/mailman/listinfo/python-list