On 1/30/07, Jan Kanis <jan.kanis@phil.uu.nl> wrote:
On Tue, 30 Jan 2007 08:19:11 +0100, Jim Jewett <jimjjewett@gmail.com> wrote:
On 1/30/07, Chris Rebert <cvrebert@gmail.com> wrote:
Also, due to the hairiness/obscurity of the construct, hardly anyone uses it, so the impact of removing it should be relatively minor.
I just did found 181 such uses in my own installation. 29 were either 3rd-party or test code, but that still leaves over 150 uses in the standard library. It is possible that some of them would also work with your semantics, or may even be bugs today -- but you would have to go through them one-by-one as part of the PEP process.
But that's certainly possible. What exactly did you search for, and what did you find?
In idle, edit menu, find in files, regex 'def.*=(\\[|\\{)(\\]|\\})' In other words, it caught "={}" or "=[]" on a def line. It did not catch other (possibly mutable) default args, nor did it catch multi-line definitions, nor did it even catch extra whitespace. I didn't notice any false positives where the "={}" was really in a comment. I didn't even look at defaults of None (let alone other singletons) to see if they were part of this idiom. They mostly seemed to be passing state, but the __init__ methods in particular may have been using a class-level variable by accident. (such as the cnf argument to Tk widgets.) I'll try to check more closely later. -jJ