22 扩展Python - 《Python 核心编程》

 1 //Pure C Version of Library (Extest1.c)
 2 
 3 #include <stdio.h>
 4 #include <stdlib.h>
 5 #include <string.h>
 6 #include "..\include\python.h"
 7 
 8 int fac(int n) {
 9     if (n < 2) return (1); // 0! == 1! == 1
10     return (n)*fac(n-1); // n! == n*(n-1)!
11 }
12 
13 static PyObject *Extest_fac(PyObject *self, PyObject *args) {
14     int res;         // parse result
15     int num;        // arg for fac()
16     PyObject* retval;    // return value
17 
18     res = PyArg_ParseTuple(args, "i", &num); // format code ‘i‘
19     if(!res) {        // TypeError
20         return NULL;
21     }
22     res = fac(num);
23     retval = (PyObject*)Py_BuildValue("i", res); // format code ‘i‘
24     return retval;
25 }
26 
27 static PyObject *Extest_fac2(PyObject *self, PyObject *args) {
28     int num;
29     if (!PyArg_ParseTuple(args, "i", &num))
30         return NULL;
31     return (PyObject*)Py_BuildValue("i", fac(num));
32 }
33 
34 char *reverse(char *s){
35     register char t, //temp
36          *p = s, //fwd
37          *q = (s + (strlen(s)-1)); //bwd
38 
39     while (p < q){ // if p < q
40         // swap & mv ptrs
41         t = *p;
42         *p++ = *q;
43         *q-- = t;
44     }
45     return s;
46 }
47 
48 static PyObject *Extest_reverse(PyObject *self, PyObject *args) {
49     char *origin;
50     if(!PyArg_ParseTuple(args, "s", &origin))
51         return NULL;
52     return (PyObject*)Py_BuildValue("s", reverse(origin));
53 }
54 
55 static PyObject *Extest_doppel(PyObject *self, PyObject *args) {
56     char *orig_str;
57     char *dupe_str;
58     PyObject *retval;
59     if(!PyArg_ParseTuple(args, "s", &orig_str))
60         return NULL;
61 
62     dupe_str = strdup(orig_str);
63     retval = (PyObject*)Py_BuildValue("ss", // format code "ss" mapping to tuple
64             dupe_str,
65             reverse(orig_str));
66     free(dupe_str);
67     return retval;
68 }
69 
70 int test(){
71     char s[BUFSIZ];
72     printf("4! == %d\n", fac(4));
73     printf("8! == %d\n", fac(8));
74     printf("12! == %d\n", fac(12));
75     strcpy(s, "abcdef");
76     printf("reversing ‘abcdef‘, we get ‘%s‘\n", 77             reverse(s));
78     strcpy(s, "madam");
79     printf("reversing ‘madam‘, we get ‘%s‘\n", 80             reverse(s));
81     return 0;
82 }
83 
84 static PyObject *Extest_test(PyObject *self, PyObject *args) {
85     test();
86     return (PyObject*)Py_BuildValue("");
87 }
88 
89 static PyMethodDef ExtestMethods[] = {
90     { "fac", Extest_fac, METH_VARARGS },
91     { "reverse", Extest_reverse, METH_VARARGS },
92     { "doppel", Extest_doppel, METH_VARARGS },
93     { "test", Extest_test, METH_VARARGS },
94     { NULL, NULL},
95 };
96 
97 void initExtest() {
98     Py_InitModule("Extest", ExtestMethods);
99 }