On Mar 10, 2011, at 6:20 PM, Eric Ongerth wrote: > So, jek, if you're listening, or anyone else -- is there an already > existing, working implementation of a Dict of Lists or Dict of Sets > collection class?
the association_proxy is always there to flatten the "object" in the middle of two relationships typically along an association - so just A->relationship->dict of B->relationship->set of C, association proxy from A to B.cs. > > > On Mar 10, 1:55 pm, Eric Ongerth <ericonge...@gmail.com> wrote: >> Ach, I did it again... proceeded as if column_mapped_collection and >> attribute_mapped_collection provide collection classes that are dicts >> of lists. No, they're just dicts of scalar values! >> >> Again and again I need dicts of lists. They seem to really fit the >> data that I tend to work with; A's related to C's indexed by B's (the >> B typically indicating the *type* of relationship between the A and >> the C). >> >> Eventually I need to work my own implementation of dict-of-lists and >> dict-of-dicts collection classes up to full strength so I can share >> them as a recipe or extension or something. >> >> On Mar 10, 1:02 pm, Eric Ongerth <ericonge...@gmail.com> wrote: >> >>> I make occasional use of alternate collection classes for my >>> sqlalchemy relationships. For example, column_mapped_collection. The >>> existing collection classes in sqlalchemy.orm.collections work really >>> well for me; I have a lot of relational data that very naturally >>> belongs in dicts rather than lists because it makes sense as one thing >>> indexed or mapped by another. >> >>> I find that I often need to add an item to one of these dict-mapped >>> collections and would rather not have to check whether the key already >>> exists in the dict. So I'm doing, essentially: >>> collection.setdefault(key, []).append(value). >> >>> As a matter of syntactic sugar (which alternative collection classes >>> already are, anyway) I would like to have collection classes backed by >>> dicts with the capability of python's defaultdict, so that I could >>> write more simply, and with equivalent results: >>> collection[key].append(value) >> >>> I understand how to create my own collection class which will behave >>> as desired. My question is, has anyone already got code for this that >>> I could borrow rather than reinvent the wheel? Thanks in advance. -- >>> Eric > > -- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To post to this group, send email to sqlalchemy@googlegroups.com. > To unsubscribe from this group, send email to > sqlalchemy+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/sqlalchemy?hl=en. > -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To post to this group, send email to sqlalchemy@googlegroups.com. To unsubscribe from this group, send email to sqlalchemy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sqlalchemy?hl=en.
