Josh Rosenberg <shadowranger+pyt...@gmail.com> added the comment:
If you're annoyed by having to use two lines, one to copy, one to call the mutating method, you can use the walrus operator: (y := x.copy()).some_method() or: (y := deepcopy(x)).some_method() Does that cover your use case? For the list case, you'd normally just do: arr = lis[::-1] but: (arr = lis.copy()).reverse() also works. Granted, not super pretty. But I'm not seeing enough cases where this ugliness is truly unavoidable (the two lines don't bother me that much, and for built-ins, there is usually a one-liner that works fine, e.g. the reversing slice as shown, sorted over list.sort, etc.). I'll note: Unconditionally calling copy.copy is fine; it knows to try the __copy__ method of the things it is called on (and most things that offer copy alias it to __copy__ or are special-cased in copy.copy as well; if they don't, they should), so you're unlikely to need to perform the "try method, fall back to copy.copy" yourself. ---------- nosy: +josh.r _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue42646> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
