Python:如何对CSV文件中的整数求和，而只对某个变量的整数求和？

import csv

with open('file.csv', 'r') as file:
    reader = csv.reader(file)

sum_variable = 0

for row in reader:
    sum_variable += int(row[variable_index])

print("求和结果为:", sum_variable)

import csv

def sum_integers_in_csv(csv_file, variable_index):
    sum_variable = 0
    with open(csv_file, 'r') as file:
        reader = csv.reader(file)
        for row in reader:
            sum_variable += int(row[variable_index])
    return sum_variable

csv_file = 'file.csv'
variable_index = 2
sum_result = sum_integers_in_csv(csv_file, variable_index)
print("求和结果为:", sum_result)