How to find sum of a certain element in 2d

Question

recLst=[["10:20","DDSFE","Dyson Digital Slim Fluffy Extra",2599.0,"Iron"],["10:25","DV8SF","Dyson V8 Slim Fluffy Plus",1799.0,"Standard"],["13:30","DDSFE","Dyson Digital Slim Fluffy Extra",2599.0,"Purple"],["13:30","DDSFE","Dyson Digital Slim Fluffy Extra",2599.0,"Iron"],["16:15","DV11F","Dyson V11 Fluffy",2899.0,"Red"],["17:25","DV8SF","Dyson V8 Slim Fluffy Plus",1799.0,"Standard"]]

for e in recLst:
            if e[1]=='DDSFF':
                print(e)

#This will be the layout
['10:20', 'DDSFE', 'Dyson Digital Slim Fluffy Extra', 2599.0, 'Iron']
['13:30', 'DDSFE', 'Dyson Digital Slim Fluffy Extra', 2599.0, 'Purple']
['13:30', 'DDSFE', 'Dyson Digital Slim Fluffy Extra', 2599.0, 'Iron']

hi, I wanna ask how do I find for the sum of the float for three of the list, the thing is that I print the three list above by using a for loop but I don't have any idea on sum three of the element up, I try using a list and append all the data that I need into it, but the list will only have item inside

I want to find the sum for the 4th element in my list, but I have no idea how since I'm using a for loop (by the way I am a new learner so pls don't scold me if I act stupid or don't understand the explanation)

Answer 1

If you're trying to sum the 4th element of the list, you could use the following:

list_sum = 0
for e in recLst:
    if e[1] == "DDSFE":
        list_sum += e[4]

print(list_sum)

This is assuming of course, each e in recLst is a list with 5 elements.

To be safe:

list_sum = 0
for e in recLst:
    if len(e) == 5 and e[1] == "DDSFE" and isinstance(e[4], float):
        list_sum += e[4]

print(list_sum)

Not sure if you need it to be this involved.

Or you could do the following:

list_sum = sum([e[3] for e in recList if len(e) == 5 and e[1] == "DDSFE" and isinstance(e[3], float)])