From bd0c9c3f8e9e5694dbb2925e1dd74c4e2d4b3ef3 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 19 May 2015 09:32:30 +0530
Subject: [PATCH] Fix incorrect sub-classing of tuple

---
 src/calibre/devices/scanner.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/calibre/devices/scanner.py b/src/calibre/devices/scanner.py
index 3c99e7fab5..becb2b6aa7 100644
--- a/src/calibre/devices/scanner.py
+++ b/src/calibre/devices/scanner.py
@@ -109,9 +109,10 @@ _USBDevice = namedtuple('USBDevice',
 
 class USBDevice(_USBDevice):
 
-    def __init__(self, *args, **kwargs):
-        _USBDevice.__init__(self, *args, **kwargs)
+    def __new__(cls, *args, **kwargs):
+        self = super(USBDevice, cls).__new__(cls, *args)
         self.busnum = self.devnum = -1
+        return self
 
     def __repr__(self):
         return (u'USBDevice(busnum=%s, devnum=%s, '