Odd unicode() behavior

[maport]

The behavior of the unicode built-in function when given a unicode
string seems a little odd to me:

>>unicode(u"abc")

u'abc'

>>unicode(u"abc", "ascii")

Traceback (most recent call last):
File "<stdin>", line 1, in ?
TypeError: decoding Unicode is not supported

I don't see why providing the encoding should make the function behave
differently when given a Unicode string. Surely unicode(s) ought to
bahave exactly the same as unicode(s,sys.getdefaultencoding())?

Any opinions?

Mike.

[Fredrik Lundh]

ma****@googlemail.com wrote:

The behavior of the unicode built-in function when given a unicode
string seems a little odd to me:

>>>unicode(u"abc")

u'abc'

>>>unicode(u"abc", "ascii")

Traceback (most recent call last):
File "<stdin>", line 1, in ?
TypeError: decoding Unicode is not supported

I don't see why providing the encoding should make the function behave
differently when given a Unicode string. Surely unicode(s) ought to
bahave exactly the same as unicode(s,sys.getdefaultencoding())?

nope.

if you omit the encoding argument, unicode() behaves pretty much like str(),
using either the __unicode__ method or __str__/__repr__ + decoding to get
a Unicode string.

see the language reference for details, e.g:

http://pyref.infogami.com/unicode

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