python-mastery/Exercises/soln3_1.md

Exercise 3.1 - Solution

# stock.py

class Stock:
    def __init__(self, name, shares, price):
        self.name = name
        self.shares = shares
        self.price = price

    def cost(self):
        return self.shares * self.price

    def sell(self, nshares):
        self.shares -= nshares

def read_portfolio(filename):
    '''
    Read a CSV file of stock data into a list of Stocks
    '''
    import csv
    portfolio = []
    with open(filename) as f:
        rows = csv.reader(f)
        headers = next(rows)
        for row in rows:
            record = Stock(row[0], int(row[1]), float(row[2]))
            portfolio.append(record)
    return portfolio

def print_portfolio(portfolio):
    '''
    Make a nicely formatted table showing stock data
    '''
    print('%10s %10s %10s' % ('name', 'shares', 'price'))
    print(('-'*10 + ' ')*3)
    for s in portfolio:
        print('%10s %10d %10.2f' % (s.name, s.shares, s.price))

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

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