Python – Extract dictionaries with values sum greater than K

Sometimes we need to filter a list of dictionaries based on the sum of their values. This is useful when working with data where you want to find records whose total values exceed a certain threshold.

Using Loop Iteration

The most straightforward approach is to iterate through each dictionary and calculate the sum of its values ?

student_scores = [
    {"Math": 14, "Science": 18, "English": 19},
    {"Math": 12, "Science": 4, "English": 16},
    {"Math": 13, "Science": 17, "English": 11},
    {"Math": 13, "Science": 16, "English": 13}
]

print("The list of dictionaries:")
print(student_scores)

K = 35
print(f"Threshold K: {K}")

result = []
for dictionary in student_scores:
    total = 0
    for key in dictionary:
        total += dictionary[key]
    if total > K:
        result.append(dictionary)

print("Dictionaries with sum greater than K:")
print(result)

The list of dictionaries:
[{'Math': 14, 'Science': 18, 'English': 19}, {'Math': 12, 'Science': 4, 'English': 16}, {'Math': 13, 'Science': 17, 'English': 11}, {'Math': 13, 'Science': 16, 'English': 13}]
Threshold K: 35
Dictionaries with sum greater than K:
[{'Math': 14, 'Science': 18, 'English': 19}, {'Math': 13, 'Science': 17, 'English': 11}, {'Math': 13, 'Science': 16, 'English': 13}]

Using sum() Function

Python's built-in sum() function provides a more concise way to calculate the total ?

student_scores = [
    {"Math": 14, "Science": 18, "English": 19},
    {"Math": 12, "Science": 4, "English": 16},
    {"Math": 13, "Science": 17, "English": 11},
    {"Math": 13, "Science": 16, "English": 13}
]

K = 35
result = []

for dictionary in student_scores:
    if sum(dictionary.values()) > K:
        result.append(dictionary)

print("Dictionaries with sum greater than K:")
print(result)

Dictionaries with sum greater than K:
[{'Math': 14, 'Science': 18, 'English': 19}, {'Math': 13, 'Science': 17, 'English': 11}, {'Math': 13, 'Science': 16, 'English': 13}]

Using List Comprehension

For a more Pythonic approach, use list comprehension to filter in one line ?

student_scores = [
    {"Math": 14, "Science": 18, "English": 19},
    {"Math": 12, "Science": 4, "English": 16},
    {"Math": 13, "Science": 17, "English": 11},
    {"Math": 13, "Science": 16, "English": 13}
]

K = 35
result = [d for d in student_scores if sum(d.values()) > K]

print("Dictionaries with sum greater than K:")
print(result)
print(f"Found {len(result)} dictionaries with sum > {K}")

Dictionaries with sum greater than K:
[{'Math': 14, 'Science': 18, 'English': 19}, {'Math': 13, 'Science': 17, 'English': 11}, {'Math': 13, 'Science': 16, 'English': 13}]
Found 3 dictionaries with sum > 35

Comparison

Conclusion

Use list comprehension with sum(d.values()) for the most Pythonic solution. The manual loop approach helps understand the logic, while sum() provides better readability than manual iteration.