diff options
Diffstat (limited to 'Modules/mathmodule.c')
| -rw-r--r-- | Modules/mathmodule.c | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c index 6e10993..9a9a815 100644 --- a/Modules/mathmodule.c +++ b/Modules/mathmodule.c @@ -3007,15 +3007,16 @@ math.perm Number of ways to choose k items from n items without repetition and with order. -It is mathematically equal to the expression n! / (n - k)!. +Evaluates to n! / (n - k)! when k <= n and evaluates +to zero when k > n. -Raises TypeError if the arguments are not integers. -Raises ValueError if the arguments are negative or if k > n. +Raises TypeError if either of the arguments are not integers. +Raises ValueError if either of the arguments are negative. [clinic start generated code]*/ static PyObject * math_perm_impl(PyObject *module, PyObject *n, PyObject *k) -/*[clinic end generated code: output=e021a25469653e23 input=f71ee4f6ff26be24]*/ +/*[clinic end generated code: output=e021a25469653e23 input=b2e7729d9a1949cf]*/ { PyObject *result = NULL, *factor = NULL; int overflow, cmp; @@ -3052,8 +3053,8 @@ math_perm_impl(PyObject *module, PyObject *n, PyObject *k) cmp = PyObject_RichCompareBool(n, k, Py_LT); if (cmp != 0) { if (cmp > 0) { - PyErr_SetString(PyExc_ValueError, - "k must be an integer less than or equal to n"); + result = PyLong_FromLong(0); + goto done; } goto error; } @@ -3121,18 +3122,21 @@ math.comb Number of ways to choose k items from n items without repetition and without order. -Also called the binomial coefficient. It is mathematically equal to the expression -n! / (k! * (n - k)!). It is equivalent to the coefficient of k-th term in -polynomial expansion of the expression (1 + x)**n. +Evaluates to n! / (k! * (n - k)!) when k <= n and evaluates +to zero when k > n. + +Also called the binomial coefficient because it is equivalent +to the coefficient of k-th term in polynomial expansion of the +expression (1 + x)**n. -Raises TypeError if the arguments are not integers. -Raises ValueError if the arguments are negative or if k > n. +Raises TypeError if either of the arguments are not integers. +Raises ValueError if either of the arguments are negative. [clinic start generated code]*/ static PyObject * math_comb_impl(PyObject *module, PyObject *n, PyObject *k) -/*[clinic end generated code: output=bd2cec8d854f3493 input=2f336ac9ec8242f9]*/ +/*[clinic end generated code: output=bd2cec8d854f3493 input=9a05315af2518709]*/ { PyObject *result = NULL, *factor = NULL, *temp; int overflow, cmp; @@ -3173,9 +3177,8 @@ math_comb_impl(PyObject *module, PyObject *n, PyObject *k) } if (Py_SIZE(temp) < 0) { Py_DECREF(temp); - PyErr_SetString(PyExc_ValueError, - "k must be an integer less than or equal to n"); - goto error; + result = PyLong_FromLong(0); + goto done; } cmp = PyObject_RichCompareBool(temp, k, Py_LT); if (cmp > 0) { |