np.ndarray description says: buffer : object exposing buffer interface
It's nice that it works with mmap:
b = mmap.mmap (...) u = np.ndarray (buffer=b ...)
but you wouldn't know it from the above description.
It doesn't look to me that the object returned by mmap exposes the buffer interface, does it?
In [26]: dir(b) Out[26]: ['__add__', '__class__', '__delattr__', '__delitem__', '__delslice__', '__doc__', '__format__', '__getattribute__', '__getitem__', '__getslice__', '__hash__', '__init__', '__len__', '__mul__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__rmul__', '__setattr__', '__setitem__', '__setslice__', '__sizeof__', '__str__', '__subclasshook__', 'close', 'find', 'flush', 'move', 'read', 'read_byte', 'readline', 'resize', 'rfind', 'seek', 'size', 'tell', 'write', 'write_byte']
On Fri, Sep 17, 2010 at 12:42, Neal Becker ndbecker2@gmail.com wrote:
np.ndarray description says: buffer : object exposing buffer interface
It's nice that it works with mmap:
b = mmap.mmap (...) u = np.ndarray (buffer=b ...)
but you wouldn't know it from the above description.
It doesn't look to me that the object returned by mmap exposes the buffer interface, does it?
The buffer interface is a C thing. You don't see Python-level methods. The cheapest way to test if an object can be made into a buffer is to try it:
In [22]: m = mmap.mmap(f.fileno(), 0)
In [23]: buffer(m) Out[23]: <read-only buffer for 0x52652c0, size -1, offset 0 at 0x5265380>
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Neal Becker -
Robert Kern