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"ValueError: Empty module name" on basic import

P: n/a
Hello everybody,

I am a newbie to python so I hope I am at the right place to expose my
problem..... :-[

I am working on linux mandrake 10.1 with python :
python -V
Python 2.3.4
I am trying o run the example which stay in the documentation in paragraph
http://www.python.org/doc/2.4.2/ext/pure-embedding.html 5.3 Pure Embedding
I download the code example from
http://www.python.org/doc/2.4.2/ext/run-func.txt
I call the file "TestOfficiel.c" and I compile it with :
gcc -g -I/usr/include/python2.3/ TestOfficiel.c -o TestOfficiel
-lpython2.3 -ldl
all is OK (or seems to be...).
as stated in the documentation I creat a file "TestPythonFoo.py" which
contain
"
def multiply(a,b):
print "Will compute", a, "times", b
c = 0
for i in range(0, a):
c = c + b
return c
"
I launch
../TestOfficiel ./TestPythonFoo.py multiply 3 2
and as a result :
ValueError: Empty module name
Failed to load "./TestPythonFoo.py"
if I try an absolute path to the python file :
../TestOfficiel `pwd`/TestPythonFoo.py multiply 3 2
I obtain :
ImportError: No module named
/space/ESOPPE_PROJET/Outils/SwigPython/swigCallPython/TestPythonFoo.py
Failed to load
"/space/ESOPPE_PROJET/Outils/SwigPython/swigCallPython/TestPythonFoo.py"
Of course the file exist :
[montmory@esoppe1 swigCallPython]$ ll
/space/ESOPPE_PROJET/Outils/SwigPython/swigCallPython/TestPythonFoo.py
-rwxrwx--x 1 montmory esoppe 126 sep 29 14:04
/space/ESOPPE_PROJET/Outils/SwigPython/swigCallPython/TestPythonFoo.py*

I found lot of post about "ValueError: Empty module name" but no clear
solution (clear for me...).
What's wrong ?
my python version?
Additionnal informations :
gcc version 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)

Thanks for your help,

best regards,

Alain


#include <Python.h>

int
main(int argc, char *argv[])
{
PyObject *pName, *pModule, *pDict, *pFunc;
PyObject *pArgs, *pValue;
int i;

if (argc < 3) {
fprintf(stderr,"Usage: call pythonfile funcname [args]\n");
return 1;
}

Py_Initialize();
pName = PyString_FromString(argv[1]);
/* Error checking of pName left out */

pModule = PyImport_Import(pName);
Py_DECREF(pName);

if (pModule != NULL) {
pDict = PyModule_GetDict(pModule);
/* pDict is a borrowed reference */

pFunc = PyDict_GetItemString(pDict, argv[2]);
/* pFun: Borrowed reference */

if (pFunc && PyCallable_Check(pFunc)) {
pArgs = PyTuple_New(argc - 3);
for (i = 0; i < argc - 3; ++i) {
pValue = PyInt_FromLong(atoi(argv[i + 3]));
if (!pValue) {
Py_DECREF(pArgs);
Py_DECREF(pModule);
fprintf(stderr, "Cannot convert argument\n");
return 1;
}
/* pValue reference stolen here: */
PyTuple_SetItem(pArgs, i, pValue);
}
pValue = PyObject_CallObject(pFunc, pArgs);
Py_DECREF(pArgs);
if (pValue != NULL) {
printf("Result of call: %ld\n", PyInt_AsLong(pValue));
Py_DECREF(pValue);
}
else {
Py_DECREF(pModule);
PyErr_Print();
fprintf(stderr,"Call failed\n");
return 1;
}
/* pDict and pFunc are borrowed and must not be Py_DECREF-ed */
}
else {
if (PyErr_Occurred())
PyErr_Print();
fprintf(stderr, "Cannot find function \"%s\"\n", argv[2]);
}
Py_DECREF(pModule);
}
else {
PyErr_Print();
fprintf(stderr, "Failed to load \"%s\"\n", argv[1]);
return 1;
}
Py_Finalize();
return 0;
}

def multiply(a,b):
print "Will compute", a, "times", b
c = 0
for i in range(0, a):
c = c + b
return c

Sep 29 '06 #1
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P: n/a
alain MONTMORY wrote:
Hello everybody,

I am a newbie to python so I hope I am at the right place to expose my
problem..... :-[

I am working on linux mandrake 10.1 with python :
python -V
Python 2.3.4
I am trying o run the example which stay in the documentation in paragraph
http://www.python.org/doc/2.4.2/ext/pure-embedding.html 5.3 Pure Embedding
I download the code example from
http://www.python.org/doc/2.4.2/ext/run-func.txt
I call the file "TestOfficiel.c" and I compile it with :
gcc -g -I/usr/include/python2.3/ TestOfficiel.c -o TestOfficiel
-lpython2.3 -ldl
all is OK (or seems to be...).
as stated in the documentation I creat a file "TestPythonFoo.py" which
contain
"
def multiply(a,b):
print "Will compute", a, "times", b
c = 0
for i in range(0, a):
c = c + b
return c
"
I launch
./TestOfficiel ./TestPythonFoo.py multiply 3 2
and as a result :
ValueError: Empty module name
Failed to load "./TestPythonFoo.py"
This is (I believe) because of the "." at the front.
if I try an absolute path to the python file :
./TestOfficiel `pwd`/TestPythonFoo.py multiply 3 2
I obtain :
ImportError: No module named
/space/ESOPPE_PROJET/Outils/SwigPython/swigCallPython/TestPythonFoo.py
It's quite correct, there never could be a module named that. The name
of your module is TestPythonFoo -- so all you should have to do is
./TestOfficiel TestPythonFoo multiply 3 2
Failed to load
"/space/ESOPPE_PROJET/Outils/SwigPython/swigCallPython/TestPythonFoo.py"
Of course the file exist :
[montmory@esoppe1 swigCallPython]$ ll
/space/ESOPPE_PROJET/Outils/SwigPython/swigCallPython/TestPythonFoo.py
-rwxrwx--x 1 montmory esoppe 126 sep 29 14:04
/space/ESOPPE_PROJET/Outils/SwigPython/swigCallPython/TestPythonFoo.py*

I found lot of post about "ValueError: Empty module name" but no clear
solution (clear for me...).
What's wrong ?
my python version?
Additionnal informations :
gcc version 3.4.1 (Mandrakelinux 10.1 3.4.1-4mdk)

Thanks for your help,

best regards,

Alain


--------------070105030901000008070407
Content-Type: text/plain
Content-Disposition: inline;
filename="TestOfficiel.c"
X-Google-AttachSize: 2022

#include <Python.h>

int
main(int argc, char *argv[])
{
PyObject *pName, *pModule, *pDict, *pFunc;
PyObject *pArgs, *pValue;
int i;

if (argc < 3) {
fprintf(stderr,"Usage: call pythonfile funcname [args]\n");
"pythonfile" is confusing; it should be "modulename".

return 1;
}

Py_Initialize();
pName = PyString_FromString(argv[1]);
/* Error checking of pName left out */

pModule = PyImport_Import(pName);
As the docs for this function say, it just calls the same routine that
is called by the __import__ built-in function. One can experiment with
that:
OS-prompt>copy con foo.py
print 'hello fubar world'
^Z
1 file(s) copied.

OS-prompt>python
Python 2.4.3 (#69, Mar 29 2006, 17:35:34) [MSC v.1310 32 bit (Intel)]
on win32
Type "help", "copyright", "credits" or "license" for more information.
>>__import__("foo")
hello fubar world
<module 'foo' from 'foo.py'>
>>__import__("foo.py")
Traceback (most recent call last):
File "<stdin>", line 1, in ?
ImportError: No module named py
>>__import__("")
Traceback (most recent call last):
File "<stdin>", line 1, in ?
ValueError: Empty module name
>>__import__(r".\foo")
Traceback (most recent call last):
File "<stdin>", line 1, in ?
ValueError: Empty module name
>>__import__(r"./foo")
Traceback (most recent call last):
File "<stdin>", line 1, in ?
ValueError: Empty module name
>>__import__(r"/foo")
Traceback (most recent call last):
File "<stdin>", line 1, in ?
ImportError: No module named /foo
>>__import__(r".foo")
Traceback (most recent call last):
File "<stdin>", line 1, in ?
ValueError: Empty module name
>>>
Hmmm ... "empty module name" is rather misleading when it starts with a
"." -- I can feel a bugfix^^^^^^ enhancement request coming on :-)

HTH,
John

Sep 29 '06 #2

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