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

In Python 3:

Short answer:

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

or:

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

or:

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

Long answer:

d.items(), basically (but not actually) gives you a list with a tuple, which has 2 values, that will look like this when printed:

dict_items([('a', 1)])

You can convert it to the actual list by wrapping with list(), which will result in this value:

[('a', 1)]

Answer 2

>>> d = {"a":1}
>>> [(k, v)] = d.items()
>>> k
'a'
>>> v
1

Or using next, iter:

>>> k, v = next(iter(d.items()))
>>> k
'a'
>>> v
1
>>>

Answer 3

d = {"a": 1}

you can do

k, v = d.keys()[0], d.values()[0]

d.keys() will actually return list of all keys and d.values() return list of all values, since you have a single key:value pair in d you will be accessing the first element in list of keys and values

Answer 4

If you just want the dictionary key and don't care about the value, note that (key, ), = foo.items() doesn't work. You do need to assign that value to a variable.

So you need (key, _), = foo.items()

Illustration in Python 3.7.2:

>>> foo = {'a': 1}
>>> (key, _), = foo.items()
>>> key
'a'
>>> (key, ), = foo.items()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: too many values to unpack (expected 1)