how to add the sum of a list in csv python code example

Example: how to sum a column in csv python using list in python

import csv
csv_file = csv.reader(open("your_file_name.csv"))

dist = 0
for row in csv_file:
    _dist = row[2]
    try: 
        _dist = float(_dist)
    except ValueError:
        _dist = 0

    dist += _dist