sum_csv.py

# sum.py
#
# Sums up a specific column in a csv, input is via PIPE
# Useful for piping multiple files in at once.

import sys
import csv

if len(sys.argv) < 2:
  print "Usage: cat file | python sum.py column#"
  exit()

col = int(sys.argv[1])

total = 0
for row in csv.reader(iter(sys.stdin.readline, '')):
  try: 
    total = total + float(row[col])
    print("value = " + row[col])
  except ValueError:
    pass

sys.stdout.write("Total : " + str(total) + "\n")