Issue #9165: Add math.isfinite and cmath.isfinite.
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 7f9372a..152788f 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -1818,6 +1818,19 @@
Convert angle x from degrees to radians.");
static PyObject *
+math_isfinite(PyObject *self, PyObject *arg)
+{
+ double x = PyFloat_AsDouble(arg);
+ if (x == -1.0 && PyErr_Occurred())
+ return NULL;
+ return PyBool_FromLong((long)Py_IS_FINITE(x));
+}
+
+PyDoc_STRVAR(math_isfinite_doc,
+"isfinite(x) -> bool\n\n\
+Check if float x is finite (not an infinity or NaN).");
+
+static PyObject *
math_isnan(PyObject *self, PyObject *arg)
{
double x = PyFloat_AsDouble(arg);
@@ -1868,6 +1881,7 @@
{"fsum", math_fsum, METH_O, math_fsum_doc},
{"gamma", math_gamma, METH_O, math_gamma_doc},
{"hypot", math_hypot, METH_VARARGS, math_hypot_doc},
+ {"isfinite", math_isfinite, METH_O, math_isfinite_doc},
{"isinf", math_isinf, METH_O, math_isinf_doc},
{"isnan", math_isnan, METH_O, math_isnan_doc},
{"ldexp", math_ldexp, METH_VARARGS, math_ldexp_doc},