deal with empty config values

screenless/bureau/bureau.py

@@ -184,14 +184,17 @@ class Bureau(object):
         printcfg = configparser.ConfigParser()
         try:
             printcfg.read("printers.cfg")
-            self.smprint = object()
-            self.smprint["vendorid"] = int(printcfg["smallprinter"]["vendorid"], 16)
-            self.smprint["prodid"] = int(printcfg["smallprinter"]["productid"], 16)
-            self.smprint["in_ep"] = int(printcfg["smallprinter"]["inep"], 16)
-            self.smprint["out_ep"] = int(printcfg["smallprinter"]["outep"], 16)
+            self.smprint = {}
+            for hexkey in ["vendorid", "productid", "inep", "outep"]:
+                val = printcfg["smallprinter"][hexkey]
+                if val == "":
+                    self.smprint[hexkey] = None
+                else:
+                    self.smprint[hexkey] = int(val, 16)
             self.smprint["width"] = int(printcfg["smallprinter"]["width"])
             self.smprint["textwidth"] = int(printcfg["smallprinter"]["textwidth"])
 
+            self.lp = {}
             self.lp["name"] = printcfg["largeprinter"]["name"]
             self.lp["papersize"] = printcfg["largeprinter"]["papersize"]
             self.lp["duplex"] = printcfg["largeprinter"].getboolean("duplex")