But after unpacking, I still cannot detect no-integer type object.

...

...

from primes import is_prime is_prime(7) True is_prime(5.5) # should raise exception, but is rounded as 5 __main__:1: DeprecationWarning: integer argument expected, got float True is_prime(9.8) # should raise exception, but is rounded as 9 False

================================= static PyObject *is_prime(PyObject *self, PyObject *arg) { PyObject *value; if (!PyArg_ParseTuple(arg, "O", value)) return NULL;

 if (PyInt_Check(value)) {
     // never raise (test case - in real its if(!PyInt_Check(value) 

which always raise) PyErr_SetString(PyExc_ValueError, "only integers are acceptable"); return NULL; } int number; if (!PyArg_ParseTuple(value, "i", &number)) return NULL;

 int result = is_prime_solve(number);

Dne 24.5.2010 8:56, Jon Parise napsal(a):

On Sun, May 23, 2010 at 7:40 AM, Vojtěch Rylkovojta.rylko@seznam.cz wrote:

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what am I doing wrong?

C code:

static PyObject *is_prime(PyObject *self, PyObject *value) { if (!PyInt_Check(value)) { PyErr_SetString(PyExc_TypeError, "only integers are acceptable"); return NULL; }

Test (I'm using integer 3):

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primes.is_prime(3)

Traceback (most recent call last): File "<stdin>", line 1, in<module> ValueError: only integers are acceptable

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The second argument ('value', in your code) is actually a tuple containing the arguments passed to your is_prime() function. You'll need to unpack the individual values from that tuple.

http://docs.python.org/extending/extending.html#extracting-parameters-in-ext...

On Mon, May 24, 2010 at 6:31 AM, Vojtěch Rylko vojta.rylko@seznam.czwrote:

PyObject *value; if (!PyArg_ParseTuple(arg, "O", value))

Shouldn't that be "&value"?

Daniel Stutzbach, Ph.D. President, Stutzbach Enterprises, LLC http://stutzbachenterprises.com

Vojtěch Rylko, 24.05.2010 13:31:

But after unpacking, I still cannot detect no-integer type object.

...

...

...

from primes import is_prime is_prime(7) True is_prime(5.5) # should raise exception, but is rounded as 5 __main__:1: DeprecationWarning: integer argument expected, got float True is_prime(9.8) # should raise exception, but is rounded as 9 False

================================= static PyObject *is_prime(PyObject *self, PyObject *arg) { PyObject *value; if (!PyArg_ParseTuple(arg, "O", value)) return NULL;

if (PyInt_Check(value)) { // never raise (test case - in real its if(!PyInt_Check(value) which always raise) PyErr_SetString(PyExc_ValueError, "only integers are acceptable"); return NULL; } int number; if (!PyArg_ParseTuple(value, "i", &number)) return NULL;

int result = is_prime_solve(number);

You should consider giving Cython a try, where the above spells

 cdef extern from "yourcode.h":
      bint is_prime_solve(int number)

 def is_prime(int number):
     """
     >>> is_prime(7)
     True
     """
     return is_prime_solve(number)

It will raise a TypeError for you if a user passes something that can't coerce to an int, or an OverflowError for something that is too large for a C int. However, note that coercion to a C int means calling int() in Python, which also works for float values. If you *really* want to prevent non-int values, you can do this:

 def is_prime(number):
     if not isinstance(number, int):
         raise TypeError("please pass an int")
     return is_prime_solve(number)

Stefan