On Wed, Feb 4, 2009 at 2:50 PM, Pierre GM pgmdevl...@gmail.com wrote:
All,
I'm a tad puzzled by the following behavior (I'm trying to correct a
bug in genfromtxt):
I'm creating an empty structured ndarray, using np.object as dtype.
a = np.empty(1,dtype=[('',np.object)])
array([(None,)],
dtype=[('f0', '|O4')])
Now, I'd like to rename the field:
a.view([('NAME',np.object)])
TypeError: Cannot change data-type for object array.
I understand why I can't change the *type* of the field, but not why I
can't change its name that way. What would be an option that wouldn't
involve creating a new array ?
Thx in advance.
___
Numpy-discussion mailing list
Numpy-discussion@scipy.org
http://projects.scipy.org/mailman/listinfo/numpy-discussion
hi, i was looking at this as well. the code in arrayobject.c doesnt
match the error string. i changed the code to do what the error string
says and seems thing to work.
i think the if-block below it should also use xor (not changed in this
patch), but i'm not a c programmer so i may be missing something
obvious.
svn diff numpy/core/src/arrayobject.c
Index: numpy/core/src/arrayobject.c
===
--- numpy/core/src/arrayobject.c(revision 6338)
+++ numpy/core/src/arrayobject.c(working copy)
@@ -6506,9 +6506,16 @@
PyErr_SetString(PyExc_TypeError, invalid data-type for array);
return -1;
}
-if (PyDataType_FLAGCHK(newtype, NPY_ITEM_HASOBJECT) ||
-PyDataType_FLAGCHK(newtype, NPY_ITEM_IS_POINTER) ||
-PyDataType_FLAGCHK(self-descr, NPY_ITEM_HASOBJECT) ||
+if (PyDataType_FLAGCHK(newtype, NPY_ITEM_HASOBJECT) ^
+PyDataType_FLAGCHK(self-descr, NPY_ITEM_HASOBJECT)) {
+PyErr_SetString(PyExc_TypeError, \
+Cannot change data-type for object \
+array.);
+Py_DECREF(newtype);
+return -1;
+}
+
+if (PyDataType_FLAGCHK(newtype, NPY_ITEM_IS_POINTER) ||
PyDataType_FLAGCHK(self-descr, NPY_ITEM_IS_POINTER)) {
PyErr_SetString(PyExc_TypeError, \
Cannot change data-type for object \
___
Numpy-discussion mailing list
Numpy-discussion@scipy.org
http://projects.scipy.org/mailman/listinfo/numpy-discussion
