[Python-Dev] [SPAM?] Re: PEP 558: Defined semantics for locals() (original) (raw)

Chris Angelico rosuav at gmail.com
Sat May 25 18:44:33 EDT 2019

On Sun, May 26, 2019 at 8:38 AM Richard Damon <Richard at damon-family.org> wrote:

On 5/25/19 5:09 PM, Nathaniel Smith wrote: > a = locals() > b = locals() > # now our first "snapshot" has changed > assert "a" in a > To me that is a static snapshot of a dynamic environment, not a dynamic snapshot. The snapshot you get at THAT moment in time won't change, as time progresses, so that snapshot itself isn't dynamic.

Except that it does. After calling locals() a second time, the result of the first call will be updated to reflect changes. It's not a frozen snapshot; you can't diff the two dictionaries to see what's changed (unless you use "a = dict(locals())" or something, which IS a snapshot).

From my reading of the description, you could also "assert a is b" - is that correct?

ChrisA

More information about the Python-Dev mailing list