I am looking for a way to determine the order of keyword parameters passed on to a class method.
In the source code the keyword parameters are ordered, an ordering that is lost by putting them into a dictionary and then accessing them by using **kw. If I had this order (either of the keyword+value pairs or just of the keywords) I could meaningfully initialise my ordereddict implemenation (which uses Key Insertion Order or KeyValue Insertion Order). I looked at traceback (which shows this info if all the keywords are on one source line), and tracing that I found that it displays the sourcecode line based on the code-object found in the frame stack. I could persue that but I find the idea of reparsing the sourcecode kind of ugly (although doable, as the keyword are never variables, and I would not have to reevaluate the variables). I am not sure if this kind of info is available internally to the interpreter (ordereddict is in C, so I would even prefer that). Has anyone done this or anything like it? I could probably compile the python interpreter to use ordereddict instead of dict and then the parser would insert the keyword parameters in specification order in the **kw ordereddict, after which iteration over parameters would be ordered. I am pretty sure though if the 10% speed overhead of the ordereddict implementation compared to dict is going to prevent people from using such an interpreter version. As an aside: I think that allowing dict to be initialised from keyword parameters (introduced in Python 2.2 IIRC) was a mistake. This kind of use of keyword parameters prevents any real keyword parameters. E.g. with 'maxsize' that restricts the dictionary size or 'unique' that would throw an Exception if an existing key gets reassigned. Anthon -- http://mail.python.org/mailman/listinfo/python-list
