Added solution code

Solutions/2_7/report.py

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+# report.py
+import csv
+
+def read_portfolio(filename):
+    '''
+    Read a stock portfolio file into a list of dictionaries with keys
+    name, shares, and price.
+    '''
+    portfolio = []
+    with open(filename) as f:
+        rows = csv.reader(f)
+        headers = next(rows)
+
+        for row in rows:
+            stock = {
+                 'name'   : row[0],
+                 'shares' : int(row[1]),
+                 'price'   : float(row[2])
+            }
+            portfolio.append(stock)
+
+    return portfolio
+
+def read_prices(filename):
+    '''
+    Read a CSV file of price data into a dict mapping names to prices.
+    '''
+    prices = {}
+    with open(filename) as f:
+        rows = csv.reader(f)
+        for row in rows:
+            try:
+                prices[row[0]] = float(row[1])
+            except IndexError:
+                pass
+
+    return prices
+
+portfolio = read_portfolio('../../Work/Data/portfolio.csv')
+prices    = read_prices('../../Work/Data/prices.csv')
+
+# Calculate the total cost of the portfolio
+total_cost = 0.0
+for s in portfolio:
+    total_cost += s['shares']*s['price']
+
+print('Total cost', total_cost)
+
+# Compute the current value of the portfolio
+total_value = 0.0
+for s in portfolio:
+    total_value += s['shares']*prices[s['name']]
+
+print('Current value', total_value)
+print('Gain', total_value - total_cost)