I would like to get the value by key index from a Python dictionary. Is there a way to get it something like this?
dic = {}
value_at_index = dic.ElementAt(index)
where index is an integer
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python
dictionary
indexing
Standard Python dictionaries are inherently unordered, so what you're asking to do doesn't really make sense.
If you really, really know what you're doing, use
value_at_index = dic.values()[index]
Bear in mind that adding or removing an element can potentially change the index of every other element.
Let us take an example of dictionary:
numbers = {'first':0, 'second':1, 'third':3}
When I did
numbers.values()[index]
I got an error:'dict_values' object does not support indexing
When I did
numbers.itervalues()
to iterate and extract the values it is also giving an error:'dict' object has no attribute 'iteritems'
Hence I came up with new way of accessing dictionary elements by index just by converting them to tuples.
tuple(numbers.items())[key_index][value_index]
for example:
tuple(numbers.items())[0][0] gives 'first'
if u want to edit the values or sort the values the tuple object does not allow the item assignment. In this case you can use
list(list(numbers.items())[index])
While you can do
value = d.values()[index]
It should be faster to do
value = next( v for i, v in enumerate(d.itervalues()) if i == index )
edit: I just timed it using a dict of len 100,000,000 checking for the index at the very end, and the 1st/values() version took 169 seconds whereas the 2nd/next() version took 32 seconds.
Also, note that this assumes that your index is not negative
If you really just want a random value from the available key range, use random.choice on the dictionary's values (converted to list form, if Python 3).
>>> from random import choice
>>> d = {1: 'a', 2: 'b', 3: 'c'}
>>>> choice(list(d.values()))
Source: Stackoverflow.com