[Numpy-discussion] Non-writeable default for numpy.ndarray
tim.hochberg at ieee.org
Fri Sep 29 11:59:06 CDT 2006
Travis Oliphant wrote:
> Tim Hochberg wrote:
>> Francesc Altet wrote:
>> It's not that the it's being built from ndarray, it's that the buffer
>> that you are passing it is read only.
> This is correct.
>> In fact, I'd argue that allowing
>> the writeable flag to be set to True in this case is actually a bug.
> It's actually intentional. Strings used as buffers are allowed to be
> writeable. This is an explicit design decision to allow pickles to load
> without making 2 copies of the memory. The pickled string that Python
> creates is used as the actual memory for loaded arrays.
> Now, I suppose it would be possible to still allow this but be more
> finnicky about when a string-used-as-the-memory can be set writeable
> (i.e. we are the only reference to it). But, this would be a fragile
> solution as well.
> My inclination is to just warn users not to use strings as buffers
> unless they know what they are doing. The fact that it is read-only by
> default is enough of a guard against "accidentally" altering a string
> you didn't want to alter.
That makes sense.
Someday, when string/unicode => bytes/string, we'll be able to use the
bytes type for this and it'll be much cleaner. But not for a while I
More information about the Numpy-discussion