On Sat, Nov 20, 2021 at 8:16 AM Chris Angelico <ros...@gmail.com> wrote: > > On Sat, Nov 20, 2021 at 8:13 AM Marco Sulla > <marco.sulla.pyt...@gmail.com> wrote: > > > > (venv_3_10) marco@buzz:~$ python > > Python 3.10.0 (heads/3.10-dirty:f6e8b80d20, Nov 18 2021, 19:16:18) > > [GCC 10.1.1 20200718] on linux > > Type "help", "copyright", "credits" or "license" for more information. > > >>> a = frozenset((3, 4)) > > >>> a > > frozenset({3, 4}) > > >>> a |= {5,} > > >>> a > > frozenset({3, 4, 5}) > > That's the same as how "x = 4; x += 1" can "alter" four into five. > > >>> a = frozenset((3, 4)) > >>> id(a), a > (140545764976096, frozenset({3, 4})) > >>> a |= {5,} > >>> id(a), a > (140545763014944, frozenset({3, 4, 5})) > > It's a different frozenset. >
Oh, even better test: >>> a = frozenset((3, 4)); b = a >>> id(a), a, id(b), b (140602825123296, frozenset({3, 4}), 140602825123296, frozenset({3, 4})) >>> a |= {5,} >>> id(a), a, id(b), b (140602825254144, frozenset({3, 4, 5}), 140602825123296, frozenset({3, 4})) ChrisA -- https://mail.python.org/mailman/listinfo/python-list