Hi Steve
I've been playing around with your two suggestions.
The Record class is an elegant solution. It doesn't however help in the case where the class has the following general data structure (something I should have stated originally):
class.config1 = param class.config2 = param class.data = { 'this' : [] 'that' : [] ... }
The __setitem__ and __getitem__ methods allow the class.data data structure to be dealt with easily as self.data[key] = val without worrying about getting involved with other variables such as config1 and config2 (because potentially a data key could be called 'config1' for example.
Yeah, if the keys of your data dict might collide with the attributes in your object, you can't make _data_ a Record type. On the other hand, you can make the items _within_ data Record types, which is what my original suggestion said. For example:
py> class Record(object):
... def __init__(self, foo, bar, dict, baz):
... self.foo = foo
... self.bar = bar
... self.dict = dict
... self.baz = baz
... def __repr__(self):
... return 'Record(%r, %r, %r, %r)' % (
... self.foo, self.bar, self.dict, self.baz)
...
py> class C(object):
... def __init__(self, config1, config2):
... self.config1 = config1
... self.config2 = config2
... self.data = dict(this=Record(1, 2, {}, 4),
... that=Record(5, 6, {}, 8))
... def __getitem__(self, item):
... return self.data[item]
...
py> c = C(True, False)
py> c['this']
Record(1, 2, {}, 4)
py> c['that']
Record(5, 6, {}, 8)
py> c['this'].foo
1
py> c['that'].bar
6
py> c['that'].baz = 42
py> c['that']
Record(5, 6, {}, 42)... def __setitem__(self, x, value): ... try: ... name, index = x ... self.data.setdefault(name, {})[index] = value ... except ValueError: ... self.data[x] = value...
py> c['one', 0] = 1
This does seem a lot more logical than my object['three'] = [0, 'val0']. Thanks for this (and using try against a possible ValueError).
No prob. Especially if you expect mostly to get items of the form (name, index), the try/except is the way to go.
STeVe -- http://mail.python.org/mailman/listinfo/python-list
