Pythonic way to access arbitrary element from dictionary [duplicate]

Question

I have a dictionary, full of items. I want to peek at a single, arbitrary item:

print("Amongst our dictionary's items are such diverse elements as: %s" % arb(dictionary)) 

I don't care which item. It doesn't need to be random.

I can think of many ways of implementing this, but they all seem wasteful. I am wondering if any are preferred idioms in Python, or (even better) if I am missing one.

def arb(dictionary): # Creates an entire list in memory. Could take a while.     return list(dictionary.values())[0]  def arb(dictionary): # Creates an entire iterator. An improvement.     for item in dictionary.values():         return item  def arb(dictionary): # No iterator, but writes to the dictionary! Twice!     key, value = dictionary.popitem()     dictionary[key] = value     return value 

I'm in a position where the performance isn't critical enough that this matters (yet), so I can be accused of premature optimization, but I am trying to improve my Python coding style, so if there is an easily understood variant, it would be good to adopt it.

Answer 1

Similar to your second solution, but slightly more obvious, in my opinion:

return next(iter(dictionary.values())) 

This works in python 2 as well as in python 3, but in python 2 it's more efficient to do it like this:

return next(dictionary.itervalues()) 

Answer 2

Avoiding the whole values/itervalues/viewvalues mess, this works equally well in Python2 or Python3

dictionary[next(iter(dictionary))] 

alternatively if you prefer generator expressions

next(dictionary[x] for x in dictionary)