[Python-Dev] Issue #16153: PyUnicode_FromFormatV() must fail if the format string is invalid (original) (raw)

Barry Warsaw barry at python.org
Mon Oct 8 23:50:55 CEST 2012

On Oct 08, 2012, at 11:23 PM, Victor Stinner wrote:

2012/10/8 Barry Warsaw <barry at python.org>:

Does anyone know if there is a good reason why PyUnicodeFromFormatV() does not fail on invalid format string, but copies the format string as-if into the result?

I would like to change this to raise a ValueError instead. PyUnicodeFromFormatV() is used by PyErrFormat(), so PyErrFormat() may now fail with a ValueError if the format string is invalid. This behavior is inherited from PyUnicodeFromFormat() which documents the current behavior, so you can't change this in backward incompatible way. Yes, the current behaviour is documented, but I consider it as a bug. Would it be possible to change the behaviour to fix a "bug"?

If it's documented to behave that way, why would you still consider it a bug? The current behavior is clearly intentional, the function is working as intended, and there may be code out there that depends on this documented functionality, or at least, it won't be prepared to handle the new exception.

Cheers, -Barry -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: not available URL: <http://mail.python.org/pipermail/python-dev/attachments/20121008/ab282ad9/attachment.pgp>

More information about the Python-Dev mailing list