Steven D'Aprano wrote: > In the midst of that discussion, Guido van Rossum made a comment about > subclassing dicts: > > [quote]
> Personally I wouldn't add any words suggesting or referring > to the option of creation another class for this purpose. You > wouldn't recommend subclassing dict for constraining the > types of keys or values, would you? > [end quote] > This surprises me, and rather than bother Python-Dev (where it will > likely be lost in the noise, and certain will be off-topic), I'm hoping > there may be someone here who is willing to attempt to channel GvR. I > would have thought that subclassing dict for the purpose of constraining > the type of keys or values would be precisely an excellent use of > subclassing. > > > class TextOnlyDict(dict): > def __setitem__(self, key, value): > if not isinstance(key, str): > raise TypeError Personally I feel dirty whenever I write Python code that defeats duck- typing -- so I would not /recommend/ any isinstance() check. I realize that this is not an argument... PS: I tried to read GvR's remark in context, but failed. It's about time to to revolt and temporarily install the FLUFL as our leader, long enough to revoke Guido's top-posting license, but not long enough to reintroduce the <> operator... -- https://mail.python.org/mailman/listinfo/python-list
