bpo-30416: Protect the optimizer during constant folding. by serhiy-storchaka · Pull Request #4860 · python/cpython

The old peephole optimizer doesn't have such limit (see bpo-30416). This is a limit for the total number of items, including nested tuples and sets. For example ((((((((1,)*20,)*20,)*20,)*20,)*20,)*20,)*20,)*20 contains around 21**8 items.

The size of every tuple and set is limited to 256 (was 20).

What the limit looks reasonable to you?