Re: [Python-Dev] __str__ and unicode
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Dec 6, 2006, at 9:15 AM, Michael Urman wrote: >> I don't have anything older than 2.4 laying around either, but IIRC >> in 2.3 unicode() did not call __unicode__(). > > It turns out __unicode__() is called on Python 2.3.5. Ah cool, thanks. I must be misremembering that about some earlier Python. - -Barry -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.5 (Darwin) iQCVAwUBRXbcenEjvBPtnXfVAQIZWAP/aRXJ1Rq0eMVWhYOYvP6Wdy2v5DCj0Arl yS3n0RURWJj5i+zYtqQUBIJEOcFSLJ69cb1SWl/KTvedI4y0SBQknX0o8EJaYhSU h1Y2gL2X+QnvJxlCf7PCdm2C1jYQgwAmKuebjCwaMPJYBqW9Z27+oSTsyFFM/mPR 2qx++VsRw68= =ABvs -END PGP SIGNATURE- ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] __str__ and unicode
> I don't have anything older than 2.4 laying around either, but IIRC > in 2.3 unicode() did not call __unicode__(). It turns out __unicode__() is called on Python 2.3.5. % python2.3 Python 2.3.5 (#2, Oct 18 2006, 23:04:45) [GCC 4.1.2 20061015 (prerelease) (Debian 4.1.1-16.1)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> class Foo(object): ... def __unicode__(self): ... print "unicode" ... return u"hi" ... def __str__(self): ... print "str" ... return "hello" ... >>> unicode(Foo()) unicode u'hi' -- Michael Urman http://www.tortall.net/mu/blog ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] __str__ and unicode
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Dec 6, 2006, at 7:07 AM, Nick Coghlan wrote: > M.-A. Lemburg wrote: >> On 2006-12-06 10:26, Fredrik Lundh wrote: >>> From what I can tell, __str__ may return a Unicode object, but >>> only if can be converted to an 8-bit string using the default >>> encoding. Is this >>> on purpose or by accident? Do we have a plan for improving the >>> situation >>> in future 2.X releases ? > > It has worked that way since at Python least 2.4 (I just tried > returning > unicode from __str__ in 2.4.1 and it worked fine). That's the > oldest version I > have handy, so I don't know if it was possible in earlier versions. I don't have anything older than 2.4 laying around either, but IIRC in 2.3 unicode() did not call __unicode__(). - -Barry -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.5 (Darwin) iQCVAwUBRXbBIHEjvBPtnXfVAQJC6AQAhPDrd451PYhQHTuFZqFX7oJpuadEONxb UaBEpWs6yzJjLAxC2tfRVT8vOc1bTmF3Wzf1y5HZsXcbklOFm3USl0YJ8206oDBN 2MGGf2e/JuC5oajo5RJqQ/oqaLDSHb8cD6GP2y/+FFaAhwDnlgnOlV0TxAggKv4K a9nCnFRwJ8c= =+mj8 -END PGP SIGNATURE- ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] __str__ and unicode
M.-A. Lemburg wrote: > On 2006-12-06 10:26, Fredrik Lundh wrote: >> From what I can tell, __str__ may return a Unicode object, but >> only if can be converted to an 8-bit string using the default encoding. Is >> this >> on purpose or by accident? Do we have a plan for improving the situation >> in future 2.X releases ? It has worked that way since at Python least 2.4 (I just tried returning unicode from __str__ in 2.4.1 and it worked fine). That's the oldest version I have handy, so I don't know if it was possible in earlier versions. > This was added to make the transition to all Unicode in 3k easier: > > .__str__() may return a string or Unicode object. > > .__unicode__() must return a Unicode object. > > There is no restriction on the content of the Unicode string > for .__str__(). It's also the basis for a tweak that was made in 2.5 to permit conversion to a builtin string in a way that is idempotent for both str and unicode instances via: as_builtin_string = '%s' % original To use the terms from the deferred PEP 349, that conversion mechanism is both Unicode-safe (unicode doesn't get coerced to str) and str-stable (str doesn't get coerced to unicode). Cheers, Nick. -- Nick Coghlan | [EMAIL PROTECTED] | Brisbane, Australia --- http://www.boredomandlaziness.org ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] __str__ and unicode
On 2006-12-06 10:56, Fredrik Lundh wrote: > M.-A. Lemburg wrote: > >> This was added to make the transition to all Unicode in 3k easier: > > thanks for the clarification. > > do you recall when this was added? 2.5? Not really, only that it was definitely before 2.5. -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Dec 06 2006) >>> Python/Zope Consulting and Support ...http://www.egenix.com/ >>> mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ >>> mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/ ::: Try mxODBC.Zope.DA for Windows,Linux,Solaris,FreeBSD for free ! ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] __str__ and unicode
M.-A. Lemburg wrote: > This was added to make the transition to all Unicode in 3k easier: thanks for the clarification. do you recall when this was added? 2.5? ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] __str__ and unicode
On 2006-12-06 10:46, M.-A. Lemburg wrote: > On 2006-12-06 10:26, Fredrik Lundh wrote: >> over at my work copy of the python language reference, Adrian Holovaty >> asked about the exact semantics of the __str__ hook: >> >> http://effbot.org/pyref/__str__ >> >>"The return value must be a string object." Does this mean it can be a >>*Unicode* string object? This distinction is ambiguous to me because >> unicode objects and string objects are both subclasses of basestring. >> May a __str__() return a Unicode object? >> >> I seem to remember earlier discussions on this topic, but don't recall when >> and what. From what I can tell, __str__ may return a Unicode object, but >> only if can be converted to an 8-bit string using the default encoding. Is >> this >> on purpose or by accident? Do we have a plan for improving the situation >> in future 2.X releases ? > > This was added to make the transition to all Unicode in 3k easier: > > .__str__() may return a string or Unicode object. > > .__unicode__() must return a Unicode object. > > There is no restriction on the content of the Unicode string > for .__str__(). One more thing, since these two hooks are commonly used with str() and unicode(): * unicode(obj) will first try .__unicode() and then revert to .__str__() (possibly converting the string return value to Unicode) * str(obj) will try .__str__() only (possibly converting the Unicode return value to a string using the default encoding) -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Dec 06 2006) >>> Python/Zope Consulting and Support ...http://www.egenix.com/ >>> mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ >>> mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/ ::: Try mxODBC.Zope.DA for Windows,Linux,Solaris,FreeBSD for free ! ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
Re: [Python-Dev] __str__ and unicode
On 2006-12-06 10:26, Fredrik Lundh wrote: > over at my work copy of the python language reference, Adrian Holovaty > asked about the exact semantics of the __str__ hook: > > http://effbot.org/pyref/__str__ > >"The return value must be a string object." Does this mean it can be a >*Unicode* string object? This distinction is ambiguous to me because > unicode objects and string objects are both subclasses of basestring. > May a __str__() return a Unicode object? > > I seem to remember earlier discussions on this topic, but don't recall when > and what. From what I can tell, __str__ may return a Unicode object, but > only if can be converted to an 8-bit string using the default encoding. Is > this > on purpose or by accident? Do we have a plan for improving the situation > in future 2.X releases ? This was added to make the transition to all Unicode in 3k easier: .__str__() may return a string or Unicode object. .__unicode__() must return a Unicode object. There is no restriction on the content of the Unicode string for .__str__(). -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source (#1, Dec 06 2006) >>> Python/Zope Consulting and Support ...http://www.egenix.com/ >>> mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ >>> mxODBC, mxDateTime, mxTextTools ...http://python.egenix.com/ ::: Try mxODBC.Zope.DA for Windows,Linux,Solaris,FreeBSD for free ! ___ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
