On 11/19/2009 08:30 AM, Mohan Ganesalingam wrote:
I believe this is impossible: Python treats strings as immutable,
which means you can't manipulate them in-place, and there is no C API
function
There is apparently one exception to this, which I was utilising:
char* PyString_AsString(PyObject *string) Returns a NUL-terminated
representation of the contents of string. The pointer refers to the
internal buffer of string, not a copy. The data must not be modified
in any way, unless the string was just created using
PyString_FromStringAndSize(NULL, size).
I.e. if you create a string using PyString_FromStringAndSize(0, n),
then you can immediately modify its contents using PyString_AsString.
AFAICS this functionality is (reasonably enough) not wrapped by
boost::python::str, so you have to use the underlying API.
OK, perhaps I misunderstood your use-case. Indeed, you may allocate a
string using the Python C API, and have a small window within which you
can manipulate its content, before handing control back to the Python
runtime. If that is what you need, great.
For avoidance of doubt: I don't think it would be valid to modify that
string after you have handed control back to Python. The Python runtime
may well create hashes from it for efficient lookup, which build on the
immutability of this type of object.
Regards,
Stefan
--
...ich hab' noch einen Koffer in Berlin...
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