Added solution code

Solutions/8_1/portfolio.py

@@ -0,0 +1,51 @@
+# portfolio.py
+
+import fileparse
+import stock
+
+class Portfolio(object):
+    def __init__(self):
+        self._holdings = []
+
+    @classmethod
+    def from_csv(cls, lines, **opts):
+        self = cls()
+        portdicts = fileparse.parse_csv(lines, 
+                                        select=['name','shares','price'], 
+                                        types=[str,int,float],
+                                        **opts)
+
+        for d in portdicts:
+            self.append(stock.Stock(**d))
+
+        return self
+
+    def append(self, holding):
+        self._holdings.append(holding)
+
+    def __iter__(self):
+        return self._holdings.__iter__()
+
+    def __len__(self):
+        return len(self._holdings)
+
+    def __getitem__(self, index):
+        return self._holdings[index]
+
+    def __contains__(self, name):
+        return any(s.name == name for s in self._holdings)
+
+    @property
+    def total_cost(self):
+        return sum(s.shares * s.price for s in self._holdings)
+
+    def tabulate_shares(self):
+        from collections import Counter
+        total_shares = Counter()
+        for s in self._holdings:
+            total_shares[s.name] += s.shares
+        return total_shares
+
+
+
+