# pcost_csv.py

import csv

import sys

def portfolio_cost(filename):

with open(filename, 'rt') as f:

rows = csv.reader(f)

headers = next(rows)

total_cost = 0

for rowno, row in enumerate(rows, start=1):

record = dict(zip(headers, row))

try:

nshares = int(record['shares'])

price = float(record['price'])

total_cost += nshares * price

except ValueError:

print(f'Row {rowno}: Bad row: {row}')

return total_cost

if len(sys.argv) == 2:

filename = sys.argv[1]

else:

filename = 'Data/portfolio.csv'

cost = portfolio_cost(filename)

print(filename)

print("Total cost:", cost)