How does Python dict.keys() Return a List and a Set?

Here, we have tasks to identify how Python dict.keys() return a list and set and print as a result. In this article, we will some examples of how Python dict.keys() return a list and a set.

Example :

Input : {'a': 1, 'b': 2, 'c': 3} , <class 'dict_keys'>
Output : <class 'list'>
              <class 'set'>
Explanation : Here, we have dict_keys() and we return it as list and set datatype.

How does Python dict.keys() Return a List and a Set?

Below are examples of how Python dict.keys() return a list and set in Python and not a key view object:

• dict.keys() Return a List
• dict.keys() Returns a Set

Basic Example

In this example, in the below code, a dictionary (`the `) is created, and its keys are obtained using `dict.keys()`. The keys are then displayed using a `print` statement, showcasing the key’s view object.

Python3

# Creating a sample dictionary
sample_dict = {'a': 1, 'b': 2, 'c': 3}

# Obtaining keys using dict.keys()
keys_view = sample_dict.keys()

# Displaying the keys
print("Keys:", keys_view)
print(type(keys_view))

Output

Keys: dict_keys(['a', 'b', 'c'])
<class 'dict_keys'>

How dict.keys() Return a List

Below are some of the examples by which dict.keys() returns a list:

Example 1: Convert to List Explicitly

In this example, in below code, a sample dictionary (`sample_dict`) is created with key-value pairs. The `dict.keys()` method is then used to obtain a view object (`keys_view`) representing the keys. Subsequently, the keys are explicitly converted to a list (`keys_list`).

Python3

# Creating a sample dictionary
sample_dict = {'a': 1, 'b': 2, 'c': 3}

# Obtaining keys using dict.keys()
keys_view = sample_dict.keys()

# Converting keys to a list
keys_list = list(sample_dict.keys())

# Displaying the list
print(type(keys_view))
print("Keys as List:", keys_list)
print(type(keys_list))

Output

<class 'dict_keys'>
Keys as List: ['a', 'b', 'c']
<class 'list'>

Example 2: Iterate Over Keys as List

In this example, in below code, a dictionary named `sample_dict` is created with key-value pairs. The `dict.keys()` method is used to obtain a view object (`keys_view`) representing the keys, which is then iterated over in a `for` loop. The keys are subsequently converted into a list (`keys_list`).

Python3

# Creating a sample dictionary
sample_dict = {'a': 1, 'b': 2, 'c': 3}

# Obtaining keys using dict.keys()
keys_view = sample_dict.keys()

# Iterating over keys
for key in keys_view:
    print("Key:", key)

# Converting keys to a list
keys_list = list(keys_view)

# Displaying the list
print(type(keys_view))
print("Keys as List:", keys_list)
print(type(keys_list))

Output

Key: a
Key: b
Key: c
<class 'dict_keys'>
Keys as List: ['a', 'b', 'c']
<class 'list'>

How dict.keys() Returns a Set

Below are some of the examples by which dict.keys() returns a set:

Example 1: Converting to a Set Explicitly

In this example, in below code, a dictionary (`sample_dict`) is created, and its keys are converted into a set (`keys_set`). The code then prints the type of the original dictionary, displays the set of keys, and prints the type of the resulting set.

Python3

# Creating a sample dictionary
sample_dict = {'a': 1, 'b': 2, 'c': 3}

# Converting keys to a set
keys_set = set(sample_dict.keys())

# Displaying the list
print(type(sample_dict))
print("Keys as Set:", keys_set)
print(type(keys_set))

Output

<class 'dict'>
Keys as Set: {'a', 'c', 'b'}
<class 'set'>