Stefan C. Kremer wrote: > Hi, > > The "fetchall()" command returns a list. Lists are mutable objects in > python. Could a valid implementation return the same list object (with > different contents) for multiple calls to fetchall() (with potentially > different preceding execute queries)?
That would be a very unusual behavior in Python. Mutable objects are normally not shared between function/method calls. If they are shared, this needs to be documented. It is possible (and common) to share immutable objects, though. The DB-API uses the latter to implement am optimization in the .execute() method: if you pass in the same command string object in subsequent calls, the implementation can choose to reuse the previously prepared access plan. Some other examples (these are all True): dict(some_dict) is not some_dict list(some_list) is not some_list tuple(some_tuple) is some_tuple str(some_str) is some_str -- Marc-Andre Lemburg eGenix.com Professional Python Services directly from the Source >>> Python/Zope Consulting and Support ... http://www.egenix.com/ >>> mxODBC.Zope.Database.Adapter ... http://zope.egenix.com/ >>> mxODBC, mxDateTime, mxTextTools ... http://python.egenix.com/ ________________________________________________________________________ ::: Try our new mxODBC.Connect Python Database Interface for free ! :::: eGenix.com Software, Skills and Services GmbH Pastor-Loeh-Str.48 D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg Registered at Amtsgericht Duesseldorf: HRB 46611 http://www.egenix.com/company/contact/ _______________________________________________ DB-SIG maillist - DB-SIG@python.org http://mail.python.org/mailman/listinfo/db-sig
