On Sat, Feb 9, 2013 at 11:31 PM, R. David Murray <rdmur...@bitdance.com> wrote: > The reason we avoid such type checks is that we prefer to operate via > "duck typing", which means that if an object behaves like the expected > input, it is accepted. Here, if we did an explicit type check for str, > it would prevent join from working on an "act alike" object that had > just enough str like methods to work correctly in os.join (for example, > some specialized object that was among other things a filename proxy). > Granted, this is pretty far-fetched for os.path.join, but the general > principle applies :)
I occasionally ponder the possibility of a time where we have a string.Text ABC, and can stop hardcoding checks for isinstance(str) everywhere :P (No, I'm not volunteering to write it. And if anyone does want to discuss it further, please start a new thread on python-ideas, as python-dev isn't the right venue) Cheers, Nick. -- Nick Coghlan | ncogh...@gmail.com | Brisbane, Australia _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
