Retry on a failed API call.

In the UI, we often need to click "Analyze" just one more time before
we get a 200 response.

Adding the logic to make that additional call automatically on error.

Author: kocielnik

isthisstockgood/DataFetcher.py

@@ -2,6 +2,7 @@
 import logging
 import isthisstockgood.RuleOneInvestingCalculations as RuleOne
 from requests_futures.sessions import FuturesSession
+from requests.adapters import HTTPAdapter, Retry
 from isthisstockgood.Active.MSNMoney import MSNMoney
 from isthisstockgood.Active.YahooFinance import YahooFinanceAnalysis
 from isthisstockgood.Active.Zacks import Zacks
@@ -147,6 +148,16 @@ def _create_session(self):
     session.headers.update({
       'User-Agent' : random.choice(DataFetcher.USER_AGENT_LIST)
     })
+
+    retries = Retry(
+        total=3,
+        backoff_factor=0.1,
+        status_forcelist=[301]
+    )
+    adapter = HTTPAdapter(max_retries=retries)
+    session.mount('http://', adapter)
+    session.mount('https://', adapter)
+
     return session
 
   def fetch_msn_money_data(self):