Hi list, two related questions: 1. Why do functions used to iterate over collections or dict members return specialized objects like
type(dict.keys()) -> class 'dict_keys' type(dict.values()) -> class 'dict_values' type(dict.items()) -> class 'dict_items' type(filter(..., ...)) -> class 'filter' type(map(..., ...)) -> class 'map' type(enumerate(...)) -> class 'enumerate' instead of returning some more general 'iterable' and 'view' objects? Are those returned objects really that different from one another that it makes sense to have individual implementations? 2. Why do these functions return iterators instead of iterables? First, I find it confusing - to me, it is the loop's job to create an iterator from the supplied iterable, and not the object that is being iterated over. And second, with this design, iterators are required to be iterables too, which is confusing as hell (at least for people coming from other languages in which the distinction is strict). Thanks, Peter -- https://mail.python.org/mailman/listinfo/python-list
