[Python-Dev] Call for prudence about PEP-572 (original) (raw)

Eric V. Smith eric at trueblade.com
Sun Jul 8 07:03:32 EDT 2018

On 7/8/2018 5:41 AM, Giampaolo Rodola' wrote:

As for "assert" what I'm concern about is the proliferation of things like this: class Foo: def init(self): assert self.x := fun1() assert self.y := fun2() assert self.z := fun3()

When I look at that my brain tells me that the main subject of the line is "assert", not the assignment, but maybe it's just because I'm not used to it. That aside there's the question of what to do when "python -O" switch is used. With this in place "-O" would acquire a new meaning, as it would disable "assert" statements AND assignments.

It has always meant "disable the assert statement and therefore any side effects the expression has". It's just that now the side effects are more obvious, or maybe easier to create. Even pre-572 I've been bitten by this, I'm ashamed to admit.

Eric

More information about the Python-Dev mailing list