On Thu, Jul 23, 2009 at 11:35 PM, Dr. Phillip M. Feldman<pfeld...@verizon.net> wrote: > > Some aspects of the Python design are remarkably clever, while others leave > me perplexed. Here's an example of the latter: Why does len() give an error > when applied to an int or float? len() should always return something; in > particular, when applied to a scalar, it should return a value of 1. Of > course, I can define my own function like this: > > def mylen(x): > if isinstance(x,int) or isinstance(x,float): return 1 > return len(x) > > But, this shouldn't be necessary.
The problem is that redefining len()/length/size that way would violate several principles of Python's design (The "Zen" of Python - http://www.python.org/dev/peps/pep-0020/). Specifically: - Explicit is better than implicit. - Special cases aren't special enough to break the rules. - Errors should never pass silently. - In the face of ambiguity, refuse the temptation to guess. If you'd explain the situation that prompts you to find this redefinition necessary, I'm sure someone can suggest a better approach. Cheers, Chris -- http://blog.rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
