Allow broken response from exchange API

api.py

@@ -61,7 +61,7 @@ def generate_requests():
 
 
 def requeue_after_error(req, e):
-    print >>sys.stderr, 'Error for %s:' % req.url, e.message
+    print >>sys.stderr, 'Error:', e.message
     status[req.url][1][0] += 0.5
     queue.put((status[req.url][1][0], req.url))
 
@@ -129,7 +129,12 @@ if __name__ == '__main__':
             stat[0] = scheduled = time.time() + interval
             queue.put((scheduled, res.request.url))
 
-            last = res.json()
+            try:
+                last = res.json()
+            except ValueError as e:
+                print >>sys.stderr, 'invalid response from %s:' % exid, e.message
+                continue
+
             for i in indices:
                 last = last[i]
             last = float(last)