Python: Convert a list of dictionaries into a list of values corresponding to the specified key

Last update on April 21 2025 12:59:36 (UTC/GMT +8 hours)

73. Extract List of Values from List of Dictionaries

Write a Python program to convert a list of dictionaries into a list of values corresponding to the specified key.

Use a list comprehension and dict.get() to get the value of key for each dictionary in lst.

Sample Solution:

Python Code:

# Define a function 'test' that takes a list of dictionaries 'lsts' and a 'key'.
def test(lsts, key):
    # Use a list comprehension to extract the value associated with the specified 'key' from each dictionary.
    return [x.get(key) for x in lsts]

# Create a list of dictionaries 'students', where each dictionary contains 'name' and 'age' keys.
students = [
    {'name': 'Theodore', 'age': 18},
    {'name': 'Mathew', 'age': 22},
    {'name': 'Roxanne', 'age': 20},
    {'name': 'David', 'age': 18}
]

# Print the original list of dictionaries.
print("Original list of dictionaries:")
print(students)

# Call the 'test' function to extract 'age' values from the 'students' list of dictionaries.
print("\nConvert a list of dictionaries into a list of values corresponding to the specified key:")
print(test(students, 'age'))

Sample Output:

Original list of dictionaries:
[{'name': 'Theodore', 'age': 18}, {'name': 'Mathew', 'age': 22}, {'name': 'Roxanne', 'age': 20}, {'name': 'David', 'age': 18}]

Convert a list of dictionaries into a list of values corresponding to the specified key:
[18, 22, 20, 18]

Flowchart:

For more Practice: Solve these Related Problems:

Write a Python program to extract values corresponding to a specified key from a list of dictionaries using list comprehension.
Write a Python program to iterate over a list of dictionaries and collect the values for a given key, handling missing keys gracefully.
Write a Python program to use the map() function to retrieve values from each dictionary for a specified key.
Write a Python program to implement a function that returns a list of values for a given key from a list of dictionaries.

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