Dictionaries

[jcm]

Dictionaries are unordered.  Maybe "dictionary" is a misleading term,
since dictionaries (the books) are in alphabetical order.  "map" might
be a better way of thinking of them.  The order entries in a
dictionary are printed is basically arbitrary.

Marcus Vinicius Laranjeira <m.laranjeira at datacraft.com.br> wrote:

> Hi folks,

> I got a big doubt... how python manages data in dictionaries ? for example:

> Python 2.2.1 (#34, Apr  9 2002, 19:34:33) [MSC 32 bit (Intel)] on win32
> Type "help", "copyright", "credits" or "license" for more information.
>  >>> dic = { 'R1': 1}
>  >>> dic
> {'R1': 1}
>  >>> dic['R2'] = 3
>  >>> dic
> {'R1': 1, 'R2': 3}
>  >>> dic['R4'] = 2
>  >>> dic
> {'R4': 2, 'R1': 1, 'R2': 3}
>  >>>

> I created a dictionary with one key 'R1' and a value of 1. Then, I inserted 
> a new item with a key 'R2' and a value of 3... It worked like I though it 
> would: appended the new item at the end of the dictionary.

> But why when I insert a new item with a key 'R4' and a value of 2 it 
> inserts it in the begining of the dictionary ????????

> How can I change the order of the items in a dictionary !?!?!?

> Thanks a lot,

> Marcus