Ray.Allen <ysj....@gmail.com> added the comment: Here is the patch, it add support to use width and precision formatters in PyUnicode_FromFormat() for type %s, %S, %R, %V, %U, %A, besides fixed two bugs, which at least I believe:
1. According to PyUnicode_FromFormat() doc: http://docs.python.org/dev/py3k/c-api/unicode.html?highlight=pyunicode_fromformat#PyUnicode_FromFormat, the "%A" should produce result of ascii(). But in the existing code, I only find code of call to ascii(object) and calculate the spaces needed for it, but not appending the ascii() output to result. Also according to my simple test, the %A doesn't work, as the following simple test function: static PyObject * getstr(PyObject *self, PyObject *args) { const char *s = "hello world"; PyObject *unicode = PyUnicode_FromString(s); return PyUnicode_FromFormat("%A", unicode); } Which should return the result of calling ascii() with the object named *unicode* as its argument. The result should be a unicode object with string "hello world". But it actually return a unicode object with string "%A". This can be fixed by adding the following line: case 'A': in step 4. 2. another bug, here is a piece of code in Object/unicodeobject.c, PyUnicode_FromFormatV(): 797 if (*f == '%') { 798 #ifdef HAVE_LONG_LONG 799 int longlongflag = 0; 800 #endif 801 const char* p = f; 802 width = 0; 803 while (ISDIGIT((unsigned)*f)) 804 width = (width*10) + *f++ - '0'; Here the variable *width* cannot be correctly calculated, because the while loop will not execute, the *f currently is definitely '%'! So the width is always 0. But currently this doesn't cause error, since the following codes will ensure width >= MAX_LONG_CHARS: 834 case 'd': case 'u': case 'i': case 'x': 835 (void) va_arg(count, int); 836 #ifdef HAVE_LONG_LONG 837 if (longlongflag) { 838 if (width < MAX_LONG_LONG_CHARS) 839 width = MAX_LONG_LONG_CHARS; 840 } 841 else 842 #endif 843 /* MAX_LONG_CHARS is enough to hold a 64-bit integer, 844 including sign. Decimal takes the most space. This 845 isn't enough for octal. If a width is specified we 846 need more (which we allocate later). */ 847 if (width < MAX_LONG_CHARS) 848 width = MAX_LONG_CHARS; (currently width and precision only apply to integer types:%d, %u, %i, %x, not string and object types:%s, %S, %R, %A, %U, %V ) To fix, the following line: 801 const char* p = f; should be: 801 const char* p = f++; just as the similar loop in step 4, and add another line: f--; after calculate width to adapting the character pointer. My patch fixed these two problems. Hoping somebody could take a look at it. ---------- keywords: +patch Added file: http://bugs.python.org/file18305/issue_7330.diff _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue7330> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
