Bugs item #1221424, was opened at 2005-06-15 11:17 Message generated for change (Comment added) made by rjs_org You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1221424&group_id=5470
Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: Python Interpreter Core Group: Python 2.4 Status: Open Resolution: None Priority: 5 Submitted By: Ray Schumacher (rjs_org) Assigned to: Neil Schemenauer (nascheme) Summary: buffer() object broken. Initial Comment: Same as: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1033720&group_id=5470: Still broken in 2.4.1...! C:\projects\temp\fftw>python ActivePython 2.4.1 Build 245 (ActiveState Corp.) based on Python 2.4.1 (#65, Mar 30 2005, 09:33:37) [MSC v.1310 32 bit (Intel)] on win32 Type "help", "copyright", "credits" or "license" for more information. >>> import Numeric >>> i = Numeric.zeros(8) >>> repr(buffer(i)) '<read-only buffer for 0x008D7200, size -1, offset 0 at 0x008D1B20>' >>> repr(buffer("")) '<read-only buffer for 0x0086A038, size -1, offset 0 at 0x008D1B20>' (Numeric v23.8) ---------------------------------------------------------------------- >Comment By: Ray Schumacher (rjs_org) Date: 2005-06-20 11:11 Message: Logged In: YES user_id=287034 No, since we have now used the PyObject_AsReadBuffer(). We use ctypes to transfer data returned from an C-API A/D driver directly to Numeric arrays via address. ---------------------------------------------------------------------- Comment By: Neil Schemenauer (nascheme) Date: 2005-06-18 10:26 Message: Logged In: YES user_id=35752 Calling PyObject_AsReadBuffer() is the proper way to get the address. It should work with older versions of Python as well. The buffer() object was changed in 2.4 to no longer keep a pointer to buffer memory, only the underlying PyObject. It would be possible to make the repr look the same as pre-2.4 Python. Do you still care? ---------------------------------------------------------------------- Comment By: Ray Schumacher (rjs_org) Date: 2005-06-17 12:04 Message: Logged In: YES user_id=287034 In 2.3, the actual adress of the first element of an array could be parsed for doing a memmove(), and now, not, which breaks some older code. If this is a "more Pythonic" feature, then OK; the previous resolution said "Fixed in bufferobject.c 2.25." without remark. I assumed that it had been restored to the previous. I now have: ptr = tpcnv[a.typecode()]() pythonapi.PyObject_AsReadBuffer(py_object(a), byref(ptr), byref(c_int())) ptr.refed_array = a instead of: split(repr(buffer(a)))[5][:-1] to get/use an address with ctypes... ---------------------------------------------------------------------- Comment By: Neil Schemenauer (nascheme) Date: 2005-06-17 10:52 Message: Logged In: YES user_id=35752 The repr of a buffer() object has indeed changed. I don't see how that's a bug though. ---------------------------------------------------------------------- Comment By: Ray Schumacher (rjs_org) Date: 2005-06-17 10:31 Message: Logged In: YES user_id=287034 repr(buffer("")) used to return: <read-only buffer for 0x0086A038, ptr 0x008D0520, size 1 at 0x008D1B20> now returns: >>> repr(buffer("")) '<read-only buffer for 0x0086A038, size -1, offset 0 at 0x008D1B20>' same as: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1033720&group_id=5470 ---------------------------------------------------------------------- Comment By: Neil Schemenauer (nascheme) Date: 2005-06-16 11:49 Message: Logged In: YES user_id=35752 Please explain exactly what you think is broken about the buffer object. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=105470&aid=1221424&group_id=5470 _______________________________________________ Python-bugs-list mailing list Unsubscribe: http://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
