CODEWITHSUNDEEP
pythonpython-3.x
user1720740
user1720740

Reputation: 848

How to fetch the key/value pair of a dictionary only containing one item?

Let's say I have dict. I don't know the key/value inside. How do I get this key and the value without doing a for loop (there is only one item in the dict).

You might wonder why I am using a dictionary in that case. I have dictionaries all over my API and I don't want the user to be lost. It's only a matter of consistency. Otherwise, I would have used a list and indexes.

Upvotes: 5

Views: 6506

Answers (4)

Martijn Pieters
Martijn Pieters

Reputation: 1124070

Use the proper data type for the job. Your goal should be to have workable code, not that you use the same data type all over the place.

If your dictionary only contains one key and one value, you can get either with indexing:

key = list(d)[0]
value = list(d.values())[0]

or to get both:

key, value = list(d.items())[0]

The list calls are needed because in Python 3, .keys(), .values() and .items() return dict views, not lists.

Another option is to use sequence unpacking:

key, = d
value, = d.values()

or for both at the same time:

(key, value), = d.items()

Upvotes: 12

dawg
dawg

Reputation: 104072

You can do this:

>>> d={1:'one'}
>>> k=list(d)[0]
>>> v=d[k]

Works in Python 2 or 3

Upvotes: 1

Charles Salvia
Charles Salvia

Reputation: 53329

Just get the first item in the dictionary using an iterator

>>> d = {"foo":"bar"}
>>> k, v = next(iter(d.items()))
>>> k
'foo'
>>> v
'bar'

Upvotes: 7

Ned Batchelder
Ned Batchelder

Reputation: 375854

d.popitem() will give you a key,value tuple.

Upvotes: 0

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