readport.py

import csv
from collections import Counter


def read_portfolio(filename):
    portfolio = []
    with open(filename) as f:
        rows = csv.reader(f)
        headers = next(rows)  # grab first line as column headings
        for row in rows:
            record = {
                'name': row[0],
                'shares': int(row[1]),
                'price': float(row[2])
            }
            portfolio.append(record)
    return portfolio

if __name__ == '__main__':
    portfolio = read_portfolio('Data/portfolio.csv')

    print('holidings > 100 shares')
    print([s for s in portfolio if s['shares'] > 100])

    print('total value of all shares')
    print(sum(s['shares'] * s['price'] for s in portfolio))

    print('all unique stock names')
    print({s['name'] for s in portfolio})

    print('all holdings')
    print([s['name'] for s in portfolio])

    print('Count the total shares of each stock')
    total = {s['name']: 0 for s in portfolio}
    for s in portfolio:
        total[s['name']] += s['shares']

    print(total)


    totals = Counter()
    for s in portfolio:
        totals[s['name']] += s['shares']

    print(totals)