On Mon, 15 Apr 2013 20:52:58 -0400, Terry Jan Reedy wrote: > On 4/15/2013 1:43 PM, Antoon Pardon wrote: > >> $ python3 >> Python 3.2.3 (default, Feb 20 2013, 17:02:41) [GCC 4.7.2] on linux2 >> Type "help", "copyright", "credits" or "license" for more information. >> >>> class vslice (slice): >> ... pass >> ... >> Traceback (most recent call last): >> File "<stdin>", line 1, in <module> >> TypeError: type 'slice' is not an acceptable base type >> >> >> It seems types and classes are still not mere synonyms. > > Some builtin classes cannot be subclassed. There is an issue to document > which better. That does not mean that it is not a class.
I think it is also important to document whether that is a language feature, or a mere restriction of the implementation. There is an important distinction to be made between: "In CPython, you cannot subclass slice or FunctionType. Other Pythons may have more, or fewer, restrictions." and: "No language that calls itself Python is permitted to allow slice and FunctionType to be subclassable." If I had a say in this, I would vote for the first case, with the possible exception of documented singleton types like NoneType and bool. -- Steven -- http://mail.python.org/mailman/listinfo/python-list