Is there any faster way to add the component in list? Maybe a loop?

Question

I want to add the last component in individual list. Doing it manually from addition operator is easy for small data set. Is there any alternative method which i can use to add those components for over 1000 of lists?

   data=[
[514.8,526.9,512,525,27942414],
[527.9, 528.5,  507.15, 510.8,  19353195],
[510    ,522.2  ,504.8  ,520.85 ,21799071],
[519.95,    523.2,  512,    515.7   ,18364451],
[510.4  ,513.85 ,494.25 ,501.85 ,17946821],
]
sum_volume=(data[0][4]+data[1][4]+data[2][4]+data[3][4]+data[4][4])
print(sum_volume)

Answer 1

Yes you can "transpose" your list, so the last column (4) would be the last list:

sum(list(zip(*data))[-1])

The part zip(*data) zips each list with each other. What zip does is:

list(zip([1, 2], [3, 4]))
[(1, 3), (2, 4)]

Or for your data:

list(zip(*data))

[(514.8, 527.9, 510, 519.95, 510.4),
 (526.9, 528.5, 522.2, 523.2, 513.85),
 (512, 507.15, 504.8, 512, 494.25),
 (525, 510.8, 520.85, 515.7, 501.85),
 (27942414, 19353195, 21799071, 18364451, 17946821)]

I use list(zip()) because zip will return an iterable object (<zip>). You can also choose to put it in a tuple, or in a for loop.

So when you unpack your data, your new rows (list indices) are the old columns.

In this case I selected the last column,[-1] but that is equal to [4] in your case.

fourth_column = list(zip(*data))[4]

Answer 2

You can use list comprehension and slice. -1 means first from last.

sum_volume = sum([d[-1] for d in data])

This equivalent to:

last_components = []
for d in data:
  last_components.append(d[-1])

sum_volume = sum(last_components)

Answer 3

This is a basic way to do that, Also easy to understand.

sum_volume=0
data=[
[514.8,526.9,512,525,27942414],
[527.9, 528.5,  507.15, 510.8,  19353195],
[510    ,522.2  ,504.8  ,520.85 ,21799071],
[519.95,    523.2,  512,    515.7   ,18364451],
[510.4  ,513.85 ,494.25 ,501.85 ,17946821],
]
for i in range(len(data)):
    sum_volume+=data[i][4]
print(sum_volume)

There is another way

data=[
[514.8,526.9,512,525,27942414],
[527.9, 528.5,  507.15, 510.8,  19353195],
[510    ,522.2  ,504.8  ,520.85 ,21799071],
[519.95,    523.2,  512,    515.7   ,18364451],
[510.4  ,513.85 ,494.25 ,501.85 ,17946821],
]

sum_volume = sum([i[4] for i in data])