Sum of different CSV columns in python

Question

I am quite new to Python and therefore this might seem easy but I am really stuck here.

I have a CSV file with values in a [525599 x 74] matrix. For each column of the 74 columns I would like to have the total sum of all 525599 values saved in one list.

I could not figure out the right way to iterate over each column and save the sum of each column in a list.

this can be done very simply with pandas (you should be able to read the docs) — chris
– chris, Commented Dec 18, 2018 at 11:03

Michel Keijzers · Accepted Answer · 2018-12-18 11:05:06Z

1

Why don't you :

create a columnTotal integer array (one index for each column).
read the file line by line, per line:
- Split the line using the comma as separator
- Convert the splitted string parts to integers
- Add the value of each column to the columnTotal array's colum index.

answered Dec 18, 2018 at 11:05

Michel Keijzers

15.4k28 gold badges100 silver badges124 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Fred · Accepted Answer · 2018-12-18 11:17:16Z

0

Since you're new to python I won't use any fancy libraries like pandas or numpy. But you should definitely check those out some time

import csv

reader = csv.reader(open('your_csv.csv', 'r'))
sums = [0] * 74
for row in reader:
    for i, element in enumerate(row):
        sums[i] += int(element)
print(sums)

edited Dec 18, 2018 at 11:17

answered Dec 18, 2018 at 11:04

Fred

1,50211 silver badges16 bronze badges

2 Comments

Jean-François Fabre Over a year ago

this just doesn't work. csv file contains strings, you have to convert to float / int first. And hardcoding the list at start is very bad practice.

Fred Over a year ago

Yeah I missed the conversion. Just edited it. Now... Do we really care about good convention when the guy is just learning Python? I just wanted to make it simple for the guy. If I cared about it I would probably just use pandas

Collectives™ on Stack Overflow

Sum of different CSV columns in python

2 Answers 2

Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related