Python 3 reference · Dictionary Methods

Python Dictionary keys() Method

Return a live view of the dictionary's keys. Supports len(), in and set operations such as & and |.

Syntax

dict.keys()

A dict_keys view.

List and test keysTry it yourself

person = {"name": "Ada", "year": 1815}
print(list(person.keys()))
print("name" in person)  # no need for .keys()

Output

['name', 'year']
True

Keys support set operationsTry it yourself

a = {"x": 1, "y": 2}
b = {"y": 3, "z": 4}
print(a.keys() & b.keys(), a.keys() - b.keys())

Output

{'y'} {'x'}

Version	Change
Python 3.0	Added

dict.values() · Return a live view of the dictionary's values, for looping or for functions such as sum() and max().
dict.items() · Return a live view of the dictionary's (key, value) pairs, used to loop over keys and values together.
Python Dictionaries · tutorial