All permutations from 2 lists

[Peter Otten]

On 02/03/2022 01:32, Rob Cliffe via Python-list wrote:

> itertools.product returns an iterator (or iterable, I'm not sure of the
> correct technical term).

There's a simple test:

iter(x) is x --> True  # iterator
iter(x) is x --> False  # iterable


So:

 >>> from itertools import product
 >>> p = product("ab", [1, 2])
 >>> iter(p) is p  # iterator
True
 >>> items = [1, 2]  # iterable
 >>> iter(items) is items
False

Another interesting property of (finite) iterators/iterables

list(iterable) == list(iterable) --> Generally True, but not guaranteed.

a = list(iterator)  # whatever
b = list(iterator)  # [] (*)

(*) Kill the coder if that doesn't hold ;)