How to extract dictionary single key-value pair in variables

Question

I have only a single key-value pair in a dictionary. I want to assign key to one variable and it\'s value to another variable. I have tried with below ways but I am getting

Answer 1

Add another level, with a tuple (just the comma):

(k, v), = d.items()

or with a list:

[(k, v)] = d.items()

or pick out the first element:

k, v = d.items()[0]

The first two have the added advantage that they throw an exception if your dictionary has more than one key, and both work on Python 3 while the latter would have to be spelled as k, v = next(iter(d.items())) to work.

Demo:

>>> d = {'foo': 'bar'}
>>> (k, v), = d.items()
>>> k, v
('foo', 'bar')
>>> [(k, v)] = d.items()
>>> k, v
('foo', 'bar')
>>> k, v = d.items()[0]
>>> k, v
('foo', 'bar')
>>> k, v = next(iter(d.items()))  # Python 2 & 3 compatible
>>> k, v
('foo', 'bar')

Answer 2

This is best if you have many items in the dictionary, since it doesn't actually create a list but yields just one key-value pair.

k, v = next(d.iteritems())

Of course, if you have more than one item in the dictionary, there's no way to know which one you'll get out.

Answer 3

You have a list. You must index the list in order to access the elements.

(k,v) = d.items()[0]

Answer 4

key = list(foo.keys())[0]
value = foo[key]

Answer 5

Use the .popitem() method.

k, v = d.popitem()

Answer 6

items() returns a list of tuples so:

(k,v) = d.items()[0]