[Python-Dev] PEP 7 and braces { .... } on if (original) (raw)

Guido van Rossum guido at python.org
Wed May 31 13:27:46 EDT 2017

I interpret the PEP as saying that you should use braces everywhere but not to add them in code that you're not modifying otherwise. (I.e. don't go on a brace-adding rampage.) If author and reviewer of a PR disagree I would go with "add braces" since that's clearly the PEP's preference. This is C code. We should play it safe.

On Wed, May 31, 2017 at 9:02 AM, Serhiy Storchaka <storchaka at gmail.com> wrote:

31.05.17 17:11, Victor Stinner пише:

I have a question on the CPython coding code for C code, the PEP 7: https://www.python.org/dev/peps/pep-0007/

""" Code structure: (...); braces are strongly preferred but may be omitted where C permits, and they should be formatted as shown: if (mro != NULL) { ... } else { ... } """ This section was updated after the creation of CPython in 1991, so as you may expect, a lot of existing C code doesn't respect this coding style. I'm trying to slowly add "missing" braces and indent as the example when I have to modify existing code. The problem is the "strongly preferred" and "omitted where C permits" part. I would like to make the PEP 7 more explicit on that part since in each review, I disagree with Serhiy who wants to omit them. Example: if (func == NULL) return NULL; versus if (func == NULL) { return NULL; } I now prefer the version with braces. It's more verbose, but it prevents bugs when the code is modified later for whatever reasons. IMHO it also makes the code easily to read and to understand. So I would suggest to modify the PEP 7 to always require braces for if. I would also suggest to require braces on "for(...) { ... }" and "while(...) { ... }". But only if the code has to be modified, not only to update the coding style. Thank you for opening this discussion Victor. I was going to open it myself. I strongly prefer using braces around "for" and "while" bodies. I dislike unconditional adding braces, but after changing PEP 7 I became always adding them in my code and asking this in reviewed code. I even made Argument Clinic generating braces around gotos. But when I asked Barry to add braces around simple statements to satisfy PEP 7 requirements, he pointed out that braces are only "strongly preferred". Since that time I allowed myself to left braces out in cases when they look cluttering. I think that PEP 7 should be more explicit about cases in what braces are required and in what they are optional. I prefer to make them optional (or even make the variant without braces preferable) in case of "if" (without "else") or "case" body containing only the single "goto", "break", "continue" or simple "return". Especially if it follows by an empty line or closing brace. Adding braces in these cases decreases readability IMHO. This is one peculiarity for which many people like (or hate) Python.

Python-Dev mailing list Python-Dev at python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/guido% 40python.org

-- --Guido van Rossum (python.org/~guido) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20170531/c72edd8e/attachment.html>

More information about the Python-Dev mailing list