Python: Combine values in python list of dictionaries

Last update on June 28 2025 12:40:20 (UTC/GMT +8 hours)

23. Combine Values in a List of Dictionaries

Write a Python program to combine values in a list of dictionaries.

Sample Solution:

Python Code:

# Import the 'Counter' class from the 'collections' module.
from collections import Counter

# Create a list 'item_list' containing dictionaries with 'item' and 'amount' as keys.
item_list = [{'item': 'item1', 'amount': 400}, {'item': 'item2', 'amount': 300}, {'item': 'item1', 'amount': 750}]

# Create an empty Counter object 'result' to store the summed amounts for each 'item'.
result = Counter()

# Iterate through the dictionaries in 'item_list' using a for loop.
for d in item_list:
    # Update the 'result' Counter by adding the 'amount' to the corresponding 'item' key.
    result[d['item']] += d['amount']

# Print the 'result' Counter, which contains the summed amounts for each 'item'.
print(result)

Sample Output:

Counter({'item1': 1150, 'item2': 300})

For more Practice: Solve these Related Problems:

Write a Python program to merge a list of dictionaries by summing values for common keys using collections.Counter.
Write a Python program to iterate through a list of dictionaries and accumulate the values of identical keys into a new dictionary.
Write a Python program to use dictionary comprehension to combine values from multiple dictionaries in a list.
Write a Python program to implement a function that consolidates a list of dictionaries into one by adding values for matching keys.

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