Why dictionary values aren't in the inserted order?

Question

When i declare a list 1,2,3,4 and i do something with it , even just print i get back the same sequence 1,2,3,4.

But when i do anything with dictionaries , they always change number sequence , like it is being sorted in a twisted way i can't understand .

test1 = [4,1,2,3,6,5]
print test1
test2 = {"c":3,"a":1,"b":2,"d":4}
print test2 

[4, 1, 2, 3, 6, 5]
{'a': 1, 'c': 3, 'b': 2, 'd': 4}

How in the world did 'a' become the first element and 'c' , even if it alphabetically sorted the dictionary it should have been 1,2,3,4 or a,b,c,d not 1,3,2,4 . wT?F @!$!@$#@!

So how do i print , get values from dictionary without changing the positions of the elements .?

Answer 1

Dictionaries in Python are unordered by definition. Use OrderedDict if you need the order in which values were inserted (it's available in Python 2.7 and 3.x).

Answer 2

dictionary sort order is undefined! Do not rely on it for anything. Look for a sorted dictionary if you really want a sorted dictionary, but usually you don't need one.

Examples:

• python 2.7, it's built in to the collections module
• Django has a SortedDict shipped with it
• 2.4-2.7 you can use the ordereddict module, you can pip install or easy_install it