"Terry Reedy" <tjre...@udel.edu> wrote in message news:ktbj9i$4au$1...@ger.gmane.org... > On 7/31/2013 9:07 AM, Antoine Pitrou wrote: >> >> I would suggest asking the psycopg2 project why they made this choice, >> and >> if they would reconsider. Returning a memoryview doesn't make much sense >> IMHO. > > I agree. > "memoryview objects allow Python code to access the internal data of an > object that supports the buffer protocol without copying." > Example: the binary image data of an image object. > They are not intended to be a standalone objects when there is an obvious > alternative (in this case, bytes).
For the record, I forwarded this to the psycopg2 list, and got the following reply from Daniele Varrazzo - <reply> Hi Frank, thank you for forwarding the thread. Until a not very long time ago, this was exactly the case: upon reading bytea we were handed over some data to pass to a libpq function to decode. The resulting decoded string was to be released by PQfreemem, and the memoryview was the right object to reconcile the lifetime of the python object with this deallocation requirement. Later things have changed: because of the change in bytea format in PostgreSQL 9.0 (the new format was the default and wasn't handled by libpq < 9.0, which created widespread problems) we wrote our own parser. As a consequence the memoryview is not really needed anymore, but we preferred to avoid breaking programs already using the current interface. So yes: bytes (and str on Py2) is definitely a better object to get in Python. It is already on the list of what I want in a version that would break compatibility in order to gain feature or improve the adapter in other ways (e.g. psycopg3). </reply> Frank -- http://mail.python.org/mailman/listinfo/python-list
