[Python-Dev] str vs. unicode (original) (raw)

Walter Dörwald walter at livinglogic.de
Wed Jan 19 12:19:14 CET 2005

Bob Ippolito wrote:

On Jan 19, 2005, at 4:40, Walter Dörwald wrote:

[...] That's cheating! ;)

My use case is an XML DOM API: unicode() should extract the character data from the DOM. For Text nodes this is the text, for comments and processing instructions this is u"" etc. To reduce memory footprint and to inherit all the unicode methods, it would be good if Text, Comment and ProcessingInstruction could be subclasses of unicode. It sounds like a really bad idea to have a class that supports both of these properties: - unicode as a base class - non-trivial result from unicode(foo) Do you REALLY think this should be True?! isinstance(foo, unicode) and foo != unicode(foo) Why don't you just call this "extract character data" method something other than unicode?

IMHO unicode is the most natural and logical choice. isinstance(foo, unicode) is just an implementation detail.

But you're right: the consequences of this can be a bit scary.

That way, you get the reduced memory footprint and convenience methods of unicode, with none of the craziness.

Without this craziness we wouldn't have discovered the problem. ;) Whether this craziness gets implemented, depends on the solution to this problem.

Bye, Walter Dörwald

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