Hi Jordan, That is true what you say about pop() behavior with stack-like objects. But the definition of pop() for a stack-like structure is stronger than that. A stack is a LIFO data structure. Therefore the pop() operation is defined to not only mutate the receiver and return the item popped but also ensure that the LAST item in the stack is removed. This makes perfect sense for a list type in python since lists are mutable sequences that have a specified order. But for dictionaries this does not hold since they are unordered sequences by definition. So for dictionaries it would not make sense for a programmer to simulate a stack-like type.
While we're on the subject I'm also curious as to why the author of the built-in list class called the method "append" to add an element to the end of a list and not something like "push". But this is not really much of a problem if the programmer could create an alias for it. Is it possible to do this in python? I know you can do it in ruby and even override methods and attributes in an existing built-in class like String for instance. --Nick On Mar 3, 2007, at 10:40 PM, MonkeeSage wrote: > Nick, > > In regards to stack-like objects, pop() implies mutation of the > reciever and returning the item 'popped' off the stack. The same > _semantic_ meaning can be used for pop() regarding dictionaries, even > though the _implementation_ would be different: dict.pop(key) mutates > the reciever and returns the value associated with the key. > > Regards, > Jordan > > -- > http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
