[Python-Dev] Python and the Unicode Character Database

["Martin v. Löwis"]

> What makes it worse, is that while superficially, Unicode versions
> follow the same X.Y.Z format as Python versions, the stability
> promises are completely different.  For example, it appears that the
> general category for the ZERO WIDTH SPACE was changed in Unicode
> 4.0.1.  I don't think a change affecting str.split(), int(), float()
> and probably numerous other library functions would be acceptable in a
> Python micro release.

Well, we managed to completely break Unicode normalization between
2.6.5 and 2.6.6, due to a bug.

You can see the Unicode Consortium's stability policy at

http://unicode.org/policies/stability_policy.html

In a sense, this is stronger than Python's backwards compatibility
promises (which allow for certain incompatible changes to occur
over time, whereas Unicode makes promises about all future versions).

Regards,
Martin