Convert a Dictionary to a List in Python

In Python, dictionaries and lists are important data structures. Dictionaries hold pairs of keys and values, while lists are groups of elements arranged in a specific order. Sometimes, you might want to change a dictionary into a list, and Python offers various ways to do this.

How to Convert a Dictionary to a List in Python

Below, are the ways to Convert a Dictionary to a List in Python.

• Using ‘items()’ Method
• Using List Comprehension
• Using zip() Function
• Using * Operator

Convert a Dictionary to a List Using ‘items()’ Method

In this example, the ‘items()’ method is used to retrieve key-value pairs from the dictionary, and then ‘list()’ is used to convert those pairs into a list of tuples.

Python3

# Sample Dictionary
sample_dict = {'a': 1, 'b': 2, 'c': 3}

# Convert Dictionary to List using items()
list_from_dict = list(sample_dict.items())

# Display the result
print(type(sample_dict))
print("Converted List:", list_from_dict)
print(type(list_from_dict))

Output

<class 'dict'>
Converted List: [('a', 1), ('b', 2), ('c', 3)]
<class 'list'>

Convert a Dictionary to a List Using List Comprehension

In this example, a list comprehension is employed to iterate over the key-value pairs obtained from ‘items()’ and create a list of tuples.

Python3

# Sample Dictionary
sample_dict = {'a': 1, 'b': 2, 'c': 3}

# Convert Dictionary to List using list comprehension
list_from_dict = [(key, value) for key, value in sample_dict.items()]

# Display the result
print(type(sample_dict))
print("Converted List:", list_from_dict)
print(type(list_from_dict))

Output

<class 'dict'>
Converted List: [('a', 1), ('b', 2), ('c', 3)]
<class 'list'>

Convert a Dictionary to a List Using zip() Function

In this example, below code uses the zip() function to convert a dictionary (sample_dict) into a list of tuples containing key-value pairs, and then prints the types of the original dictionary, the converted list.

Python3

# Sample Dictionary
sample_dict = {'a': 1, 'b': 2, 'c': 3}

# Convert Dictionary to List using zip()
list_from_dict = list(zip(sample_dict.keys(), sample_dict.values()))

# Display the result
print(type(sample_dict))
print("Converted List:", list_from_dict)
print(type(list_from_dict))

Output

<class 'dict'>
Converted List: [('a', 1), ('b', 2), ('c', 3)]
<class 'list'>

Convert a Dictionary to a List Using * Operator

Python’s dictionary unpacking feature, using the `*` operator, allows for a concise conversion of a dictionary to a list.

Python3

# Sample Dictionary
sample_dict = {'a': 1, 'b': 2, 'c': 3}

# Converting to List using Dictionary unpacking
list_from_dict = [*sample_dict.items()]

# Output
print(type(sample_dict))
print("Converted List:", list_from_dict)
print(type(list_from_dict))

Output

<class 'dict'>
Converted List: [('a', 1), ('b', 2), ('c', 3)]
<class 'list'>

Conclusion

In conclusion, converting a dictionary to a list in Python is a straightforward process with multiple approaches. Depending on your specific use case, you can choose between extracting keys, values, or key-value pairs. Whether you prefer the simplicity of the `list()` function, the elegance of list comprehensions, or the versatility of the `zip()` function, these methods provide the flexibility needed to adapt your data structures to various programming scenarios.