Sergey Kishchenko wrote:
In Python empty container equals False in 'if' statements:# prints "It's ok" if not []: print "It's ok" Let's create a simple Foo class: class Foo: pass Now I can use Foo objects in 'if' statements: #prints "Ouch!" f=Foo() if f: print "Ouch!" So, default __nonzero__ impl is to return True. I think, this behaviour conflicts with 'Explicit is better than implicit' and 'Practicality beats purity' statements. I think, throwing a TypeError exception would be better. It will result in more explicit code with fewer errors.
Sensible (and documented) defaults pervade Python. -- http://mail.python.org/mailman/listinfo/python-list
