Python: Get sum of a key value in multiple lists of dictionaries based on another key value-CodePudding

I have three lists:

listA = [{'fund_type_id': 1, 'fund_value': 60.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 20.0}]

ListB = [{'fund_type_id': 1, 'fund_value': 40.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 10.0}]

ListC = [{'fund_type_id': 1, 'fund_value': 20.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 30.0}]

I need to sum fund_value from listA and listC and subtract fund_value from listB for each fund_type_id (listA_fund_value - listB_fund_value listC_fund_value)

expectedList = [{'fund_type_id': 1, 'fund_value': 40.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 40.0}]

What's the most efficient and cleanest way of performing this calculation?

CodePudding user response：

This will generate what you're looking for but it is not robust as it implicitly assumes that the dictionaries are structured exactly as per your sample data:

listA = [{'fund_type_id': 1, 'fund_value': 60.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 20.0}]
listB = [{'fund_type_id': 1, 'fund_value': 40.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 10.0}]
listC = [{'fund_type_id': 1, 'fund_value': 20.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 30.0}]

el = []

for a, b, c in zip(listA, listB, listC):
    v = a['fund_value']   c['fund_value'] - b['fund_value']
    el.append({'fund_type_id': a['fund_type_id'], 'fund_value': v})

print(el)

Output:

[{'fund_type_id': 1, 'fund_value': 40.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 40.0}]

CodePudding user response：

You can use the zip() built-in and a list comprehension:

listA = [{'fund_type_id': 1, 'fund_value': 60.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 20.0}]

listB = [{'fund_type_id': 1, 'fund_value': 40.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 10.0}]

listC = [{'fund_type_id': 1, 'fund_value': 20.0}, {'fund_type_id': 2, 'fund_value': 50.0}, {'fund_type_id': 3, 'fund_value': 30.0}]

result = [{
    'fund_type_id': a['fund_type_id'],
    'fund_value': a['fund_value'] - b['fund_value']   c['fund_value']
} for a, b, c in zip(listA, listB, listC)] 
print(result)