[Cython] Fixing NumPy support for Python 3 (Stefan, please help!)

[Stefan Behnel]

Lisandro Dalcin, 18.02.2011 15:38:
> On 18 February 2011 02:19, Stefan Behnel<stefan_ml at behnel.de>  wrote:
>> Lisandro Dalcin, 17.02.2011 17:24:
>>>
>>>
>>> OK, I've found an alternative workaround. What do you think?
>>>
>>> diff --git a/Cython/Compiler/Interpreter.py
>>> b/Cython/Compiler/Interpreter.py
>>> index 83cb184..9fb5fe5 100644
>>> --- a/Cython/Compiler/Interpreter.py
>>> +++ b/Cython/Compiler/Interpreter.py
>>> @@ -6,6 +6,7 @@ For now this only covers parse tree to value conversion of
>>>   compile-time values.
>>>   """
>>>
>>> +import sys
>>>   from Nodes import *
>>>   from ExprNodes import *
>>>   from Errors import CompileError
>>> @@ -44,6 +45,10 @@ def interpret_compiletime_options(optlist, optdict,
>>> type_env=None, type_args=())
>>>               else:
>>>                   raise CompileError(node.pos, "Type not allowed here.")
>>>           else:
>>> +            if (sys.version_info[0]>=3 and
>>> +                isinstance(node, StringNode) and
>>> +                node.unicode_value is not None):
>>> +                return (node.unicode_value, node.pos)
>>>               return (node.compile_time_value(empty_scope), node.pos)
>>>
>>>       if optlist:
>>> @@ -52,6 +57,7 @@ def interpret_compiletime_options(optlist, optdict,
>>> type_env=None, type_args=())
>>>           assert isinstance(optdict, DictNode)
>>>           new_optdict = {}
>>>           for item in optdict.key_value_pairs:
>>> -            new_optdict[item.key.value] = interpret(item.value,
>>> item.key.value)
>>> +            new_key, dummy = interpret(item.key, None)
>>> +            new_optdict[new_key] = interpret(item.value, item.key.value)
>>>           optdict = new_optdict
>>>       return (optlist, new_optdict)
>>
>> This still isn't something that looks right. It just does the same thing at
>> a different place. Actually, I'm not sure there is a way to "get it right".
>>
>
> IIUC, the purpose of that code is to bring stuff from .pyx code to
> Python world at Cython runtime, that code is trying to "coerce" a
> DictNode object to a regular Python dict to be used later for
> implementing compiler directives. So, if your pyx/pxd says
> {"mode":"strided"} , and that is going to be compiler directive
> options, you need to map StringNode ->  __builtin__.str (and then use
> node.value in Py3 or node.unicode_value in Py3).
>
> Stefan, look at numpy.pxd, you will see $cdef __cythonbufferdefaults__
> = {"mode": "strided"}$. W need to "convert" that declaration in a
> regular Python dict to be used in Buffer.py, in such a way that
> $"mode" in option_dict$ or $option_dict["mode"]$ work. Currently, in
> Python 3, the key,value pair endup being bytes, then things fails...
>
> I still think that what I'm doing is not so bad. After all, I'm
> hacking a method called  interpret_compiletime_options(), the purpose
> of its output is not code generation.

Hmm, right. I guess that'll do then.

Please go ahead and push this in. If it helps NumPy users in Py3, it's 
worth getting out rather sooner than later.

Stefan