How to sort a list of dictionaries by a specific field?

To sort a list of dictionaries by a specific field, you can use the sorted() function with the key parameter or the list method .sort().

Example with sorted():

# Original list of dictionaries
data = [
    {'name': 'Bob', 'age': 30},
    {'name': 'Alice', 'age': 25},
    {'name': 'Charlie', 'age': 35}
]

# Sorting by the 'age' field
sorted_data = sorted(data, key=lambda x: x['age'])

# print(sorted_data)  # Output the sorted list

Example with .sort():

# Original list of dictionaries
data = [
    {'name': 'Bob', 'age': 30},
    {'name': 'Alice', 'age': 25},
    {'name': 'Charlie', 'age': 35}
]

# Sorting the list in place by the 'name' field
data.sort(key=lambda x: x['name'])

# print(data)  # Output the sorted list

Both approaches use an anonymous lambda function that extracts the key value for sorting. The sorted() function returns a new sorted list, while .sort() sorts the list in place.

You can also use the operator.itemgetter function for a more concise syntax:

import operator

# Original list of dictionaries
data = [
    {'name': 'Bob', 'age': 30},
    {'name': 'Alice', 'age': 25},
    {'name': 'Charlie', 'age': 35}
]

# Sorting by 'age' using itemgetter
sorted_data = sorted(data, key=operator.itemgetter('age'))

# print(sorted_data)  # Output the sorted list

For reverse sorting, add the reverse=True parameter:

import operator

# Original list of dictionaries
data = [
    {'name': 'Bob', 'age': 30},
    {'name': 'Alice', 'age': 25},
    {'name': 'Charlie', 'age': 35}
]

# Sorting by 'age' in reverse order
sorted_data_reverse = sorted(data, key=operator.itemgetter('age'), reverse=True)

# print(sorted_data_reverse)  # Output the list sorted in reverse