Could do with some decorators for the __unicode__ and __str__ rename about six HOT 7 CLOSED

Pull request #48 was merged.

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Original comment by Tom Grainger (Bitbucket: graingert, GitHub: graingert):

@benadmin Cool, just pulling the code in from Django

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Since Django's decorator seems to have proved itself, I don't mind including it. Someone should submit a PR.

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This surprisingly tricky. We want something which

• Plays nicely with inheritance.
• Allows minimal code duplication in client's code.
• Provides a reasonable fallback implementation if it's desired.

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Original comment by Aymeric Augustin (Bitbucket: aaugustin, GitHub: aaugustin):

The Python docs offer a variety of porting techniques. In the paragraph you're referring to, the result is Python 2 code that also works on Python 3 (ie. it defines a Python 2-style __unicode__ method).

While porting Django, I was very careful to write Python 3 code that also works on Python 2 rather than the opposite.

I made this choice for Django because I prefer looking at the future than at the past. And since I was building the bike shed I could chose its color :) This technique involves much more work than just trying to get tests to pass under Python 3. It may or may not suit everyone's tastes.

(Accidentally posted while I was writing my comment -- sorry if you got a notification with an incomplete message).

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Original comment by Tom Grainger (Bitbucket: graingert, GitHub: graingert):

Using a UnicodeMixin similar to django.utils.encoding.StrAndUnicode is recommended in the python 3 porting documentation.

• Why was that deprecated in django?
• Should it be removed from this porting documentation also?

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Original comment by Aymeric Augustin (Bitbucket: aaugustin, GitHub: aaugustin):

StrAndUnicode is deprecated; Django now uses:
https://github.com/django/django/blob/ef017a5f00/django/utils/encoding.py#L49

I'm the author of this code and I must admit it has some drawbacks:

• Decorated __str__ methods must return unicode strings even on Python 2;
• It's easy to shoot oneself into the foot when combining this with inheritance;
• Specifically, if you accidentally trigger infinite recursion when a base class derives __unicode__ from __str__ or vice-versa, you're in an ugly situation, because you cannot even print the problematic object! (Yes I'm looking at you django.db.models.Model.)

Of course, this technique also has some advantages — namely, it allows for reasonably short and explicit code.

I'd be very happy if that was included in six. We could remove code from Django! I just wanted to state the drawbacks upfront :)

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