On May 11, 10:47 am, Terry Reedy <tjre...@udel.edu> wrote: > anuraguni...@yahoo.com wrote: > > so unicode(obj) calls __unicode__ on that object > > It will look for the existence of type(ob).__unicode__ ... > > > and if it isn't there __repr__ is used > > According to the below, type(ob).__str__ is tried first. > > > __repr__ of list by default return a str even if __repr__ of element > > is unicode > > From the fine library manual, built-in functions section: > (I reccommend using it, along with interactive experiments.) > > "repr( object) > Return a string ..." > > "str( [object]) > Return a string ..." > > "unicode( [object[, encoding [, errors]]]) > > Return the Unicode string version of object using one of the following > modes: > > If encoding and/or errors are given, ... > > If no optional parameters are given, unicode() will mimic the behaviour > of str() except that it returns Unicode strings instead of 8-bit > strings. More precisely, if object is a Unicode string or subclass it > will return that Unicode string without any additional decoding applied. > > For objects which provide a __unicode__() method, it will call this > method without arguments to create a Unicode string. For all other > objects, the 8-bit string version or representation is requested and > then converted to a Unicode string using the codec for the default > encoding in 'strict' mode. > " > > 'unicode(somelist)' has no optional parameters, so skip to third > paragraph. Somelist is not a unicode instance, so skip to the last > paragraph. If you do dir(list) I presume you will *not* see > '__unicode__' listed. So skip to the last sentence. > unicode(somelist) == str(somelist).decode(default,'strict'). > > I do not believe str() and repr() are specifically documented for > builtin classes other than the general description, but you can figure > that str(collection) or repr(collection) will call str or repr on the > members of the collection in order to return a str, as the doc says. Thanks for the explanation.
> (Details are available by experiment.) Str(uni_string) encodes with the > default encoding, which seems to be 'ascii' in 2.x. I am sure it uses > 'strict' errors. > > I would agree that str(some_unicode) could be better documented, like > unicode(some_str) is. > > > so my only solution looks like to use my own list class everywhere i > > use list > > class mylist(list): > > def __unicode__(self): > > return u"["+u''.join(map(unicode,self))+u"]" > > Or write a function and use that instead, or, if and when you can, > switch to 3.x where str and repr accept and produce unicode. > > tjr -- http://mail.python.org/mailman/listinfo/python-list
