How do you get keys in python?

❮ Dictionary Methods

Example

Return the keys:

car = {
  "brand": "Ford",
  "model": "Mustang",
  "year": 1964
}

x = car.keys()

print(x)

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Definition and Usage

The keys() method returns a view object. The view object contains the keys of the dictionary, as a list.

The view object will reflect any changes done to the dictionary, see example below.

Syntax

Parameter Values

No parameters

More Examples

Example

When an item is added in the dictionary, the view object also gets updated:

car = {
  "brand": "Ford",
  "model": "Mustang",
  "year": 1964
}

x = car.keys()

car["color"] = "white"

print(x)

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❮ Dictionary Methods

The keys() method in Python Dictionary, returns a view object that displays a list of all the keys in the dictionary in order of insertion using Python.

Syntax: dict.keys()

Parameters: There are no parameters.

Returns: A view object is returned that displays all the keys. This view object changes according to the changes in the dictionary.

Method 1: Accessing the key using the keys() function

A simple example to show how the keys() function works in the dictionary.

Python3

Dictionary1 = {'A': 'Geeks', 'B': 'For', 'C': 'Geeks'}

print(Dictionary1.keys())

Output: 

dict_keys(['A', 'B', 'C'])

Method 2: Python access dictionary by key

Demonstrating the practical application of keys() using the Python loop.

Python3

test_dict = {"geeks": 7, "for": 1, "geeks": 2}

j = 0

for i in test_dict:

    if (j == 1):

        print('2nd key using loop : ' + i)

    j = j + 1

Output: 

2nd key using loop : for
TypeError: 'dict_keys' object does not support indexing 

Note: The second approach would not work because dict_keys in Python 3 do not support indexing. 

Method 3: Accessing key using keys() indexing

Here, we first extracted all the keys and then we implicitly converted them into the Python list to access the element from it.

Python3

test_dict = {"geeks": 7, "for": 1, "geeks": 2}

print('2nd key using keys() : ', list(test_dict.keys())[1])

Output: 

2nd key using keys() :  for

Method 4: Python Dictionary update() function

To show how to update the dictionary keys using the update() function. Here, when the dictionary is updated, keys are also automatically updated to show the changes.

Python3

Dictionary1 = {'A': 'Geeks', 'B': 'For'}

print("Keys before Dictionary Updation:")

keys = Dictionary1.keys()

print(keys)

Dictionary1.update({'C': 'Geeks'})

print('\nAfter dictionary is updated:')

print(keys)

Output: 

Keys before Dictionary Updation:
dict_keys(['B', 'A'])

After dictionary is updated:
dict_keys(['B', 'A', 'C'])

How do you create a key in Python?

How do you use keys in Python?

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How will u get all the keys in the dictionary?