I tried the code below with Python 2.x. For a given str or unicode object, it
copies the
bytes in memory (char*) to a list of 1-character strings. I'm getting
"hello" = ['h', 'e', 'l', 'l', 'o']
u"hello" = ['h', '\x00', 'e', '\x00', 'l', '\x00', 'l', '\x00', 'o', '\x00']
U"hello" = ['h', '\x00', 'e', '\x00', 'l', '\x00', 'l', '\x00', 'o', '\x00']
on platforms with sizeof(PY_UNICODE_TYPE) = 2 and
"hello" = ['h', 'e', 'l', 'l', 'o']
u"hello" = ['h', '\x00', '\x00', '\x00', 'e', '\x00', '\x00', '\x00', 'l',
'\x00', '\x00', '\x00', 'l', '\x00', '\x00', '\x00', 'o', '\x00', '\x00',
'\x00']
U"hello" = ['h', '\x00', '\x00', '\x00', 'e', '\x00', '\x00', '\x00', 'l',
'\x00', '\x00', '\x00', 'l', '\x00', '\x00', '\x00', 'o', '\x00', '\x00',
'\x00']
on platforms with sizeof(PY_UNICODE_TYPE) = 4.
Will the results be different using Python 3?
I have quite a few C++ functions with const char* arguments, expecting one byte
per character.
> - convert char* and std::string to/from Python 3 unicode string.
How would this work exactly?
Is the plan to copy the unicode data to a temporary one-byte-per-character
buffer?
----- Original Message ----
From: Stefan Seefeld <seef...@sympatico.ca>
To: Development of Python/C++ integration <cplusplus-sig@python.org>
Sent: Wednesday, March 18, 2009 11:18:03 AM
Subject: Re: [C++-sig] Some thoughts on py3k support
Haoyu Bai wrote:
>
> Yes of course we should allow users to set policy. So the problem is
> what the default behavior should be when there is no policy set by
> user explicitly. The candidates are:
>
> - raise an error
> - convert char* and std::string to/from Python bytes
> - convert char* and std::string to/from Python 3 unicode string.
>
> I personally like the last one because it would keep most of the
> existing code compatible.
>
I agree.
Thanks,
Stefan
boost::python::list
str_or_unicode_as_char_list(
boost::python::object const& O)
{
PyObject* obj = O.ptr();
boost::python::ssize_t n;
const char* c;
if (PyString_Check(obj)) {
n = PyString_GET_SIZE(obj);
c = PyString_AS_STRING(obj);
}
else if (PyUnicode_Check(obj)) {
n = PyUnicode_GET_DATA_SIZE(obj);
c = PyUnicode_AS_DATA(obj);
}
else {
throw std::invalid_argument("str or unicode object expected.");
}
boost::python::list result;
for(boost::python::ssize_t i=0;i<n;i++) {
result.append(std::string(c+i, 1u));
}
return result;
}
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