exception handling in _get_flag and documentation update

README.txt

@@ -18,7 +18,7 @@ Your first feature flag
 1. Create a new feature flag on your [dashboard](https://app.launchdarkly.com)
 2. In your application code, use the feature's key to check wthether the flag is on for each user:
 
-        if client.get_flag("your.flag.key", {"key": "user@test.com"}, false):
+        if client.get_flag("your.flag.key", {"key": "user@test.com"}, False):
             # application code to show the feature
         else:
             # the code to run if the feature is off

ldclient/__init__.py

@@ -40,12 +40,18 @@ def _get_flag(self, key, user, default):
              'User-Agent': 'PythonClient/' + __version__}
         uri = self._config._base_uri + '/api/eval/features/' + key
         r = self._session.get(uri, headers=hdrs, timeout = (self._config._connect, self._config._read))
-        dict = r.json()
-        val = _evaluate(dict, user)
-        if val is None:
-            return default
+        try:
+            dict = r.json()
+        except ValueError:
+            # expected if parsing a non 2xx response
+            logging.exception(
+                'Received non 2xx HTTP response in get_flag. '
+                'Returning default value for flag. Check feature settings.'
+            )
+            return default  
         else:
-            return val
+            return _evaluate(dict, user) or default
+
 
 def _param_for_user(feature, user):
     if 'key' in user: