On 21Dec2020 08:09, Cameron Simpson <cs at cskk.id.au> wrote: >>b = ((x[0] for x in a)) > >This is a generator comprehension, and _not_ a list. I should amend this: a "generator _expression_", not comprehension. A "generator comprehension" is not a thing. Apologies, Cameron Simpson <cs at cskk.id.au>