Raymond Hettinger wrote:
It isn't really stringiness that matters, it is that you have to terminate even though you still have an iterable container.
Guido had at least a start in Searchable, back when ABC were still in the sandbox:
Have to disagree here. An object cannot know in general whether a flattener wants to split it or not. That is an application dependent decision. A better answer is be able to tell the flattener what should be considered atomic in a given circumstance.
A while back (a couple of years I think), we had a discussion on python-list about flatten in which I posted the following version of a flatten function. It turned out to be nearly twice as fast as any other version.
def flatten(L): """ Flatten a list in place. """ i = 0 while i < len(L): while type(L[i]) is list: L[i:i+1] = L[i] i += 1 return L
For this to work the object to be flattened needs to be both mutable and list like. At the moment I can't think of any reason I would want to flatten anything that was not list like.
To make it a bit more flexible it could be changed just a bit.
def flatten(L): """ Flatten a list in place. """ objtype = type(L) i = 0 while i < len(L): while type(L[i]) is objtype: L[i:i+1] = L[i] i += 1 return L
Generally, I don't think you would want to flatten dissimilar objects.