[Tutor] Python dictionary element order

[tpc at csua.berkeley.edu]

hi everybody, I am confused about the default element order for keys of
type string in Python dictionary.

<code>
fruitlist = ['apple', 'grape', 'orange', 'pear', 'watermelon', 'mango']
eaten = {}
while fruitlist:
        fruit = fruitlist.pop()
        if fruit not in eaten:
		eaten[fruit] = 1
</code>
eaten outputs
{'grape': 1, 'apple': 1, 'pear': 1, 'mango': 1, 'watermelon': 1, 'orange':
1}

When I input a list of numbers:

<code>
numlist = [1, 2, 3, 4, 5, 6]
numdict = {}
while numlist:
	num = numlist.pop()
	if num not in numdict:
		numdict[num] = 'NULL'
</code>
numdict outputs
{1: 'NULL', 2: 'NULL', 3: 'NULL', 4: 'NULL', 5: 'NULL', 6: 'NULL'}

I understand list.pop() outputs the last element in the list, so
the dictionary element order indicated to me there was some kind of
default sorting.  The first element in eaten should be 'mango', or at the
very least 'apple' if Python dictionaries by default sort keys of type string
alphabetically.

What is going on here ?