Definition
A programming style which does not look at an object’s type to determine
if it has the right interface; instead, the method or attribute is simply
called or used (“If it looks like a duck and quacks like a duck, it
must be a duck.”) By emphasizing interfaces rather than specific types,
well-designed code improves its flexibility by allowing polymorphic
substitution. Duck-typing avoids tests using type() or
isinstance(). (Note, however, that duck-typing can be complemented
with abstract base classes.) Instead, it
typically employs hasattr() tests or EAFP programming.