The has_key() method is limited as opposed to the 'in' statement! I have a
proof.


TUPLE ('in' statement):  WORKS!
> >> fruit_basket = ("banana", "orange")
> >> "orange" in fruit_basket
True


TUPLE (has_key method):  NOT WORKING!
> >> fruit_basket = ("banana", "orange")
> >> "orange" in fruit_basket
Traceback (most recent call last):
  File "<stdin> ", line 1, in <module>
AttributeError: 'tuple' object has no attribute 'has_key'


LIST ('in' statement):  WORKS!
> >> fruit_basket = ["banana", "orange"]
> >> "orange" in fruit_basket
True


LIST (has_key method):  NOT WORKING!
> >> fruit_basket = ["banana", "orange"]
> >> fruit_basket.has_key("orange")
Traceback (most recent call last):
  File "<stdin> ", line 1, in <module>
AttributeError: 'list' object has no attribute 'has_key'


DICTIONARY ('in' statement):  WORKS!
> >> fruit_basket = {"banana": 123, "orange": 456}
> >> "orange" in fruit_basket
True


DICTIONARY (has_key method):  WORKS!
> >> fruit_basket = {"banana": 123, "orange": 456}
> >> fruit_basket.has_key("orange")
True


As you see, the 'in' statement gives more clean code and works on tuples,
lists, and dictionaries. The poor old has_key() method works only on
dictionary objects. No wonder Guido removed this stupid method out of Python
in version 3.0. And you still prefer the has_key method?