Make doctest regression test friendly

Author: svardfredrik

stock_alerter/readme.txt

@@ -9,10 +9,10 @@ are going to be processed. A simple dictionary will do.
 >>> from stock_alerter.stock import Stock
 >>> exchange = {"GOOG": Stock("GOOG"), "AAPL": Stock("AAPL")}
 >>> for key in sorted(exchange.keys()):
-...    print(key, exchange[key])
+...    print(key, str(exchange[key]))
 ...    
-AAPL       <stock_alerter.stock.Stock object at 0x0...>
-GOOG       <stock_alerter.stock.Stock object at 0x0...>
+AAPL Stock("AAPL")
+GOOG Stock("GOOG")
 
 Next, we configure the reader. The reader is the source from where the
 stock updates are coming. The module provides two readers out of the

stock_alerter/stock.py

@@ -20,6 +20,10 @@ def __init__(self, symbol):
         self.history = TimeSeries()
         self.updated = Event()
 
+    def __str__(self):
+        class_name = type(self).__name__
+        return '{}("{}")'.format(class_name, self.symbol)
+
     @property
     def price(self):
         """Returns the current price of the Stock