runtimeerror missing handler python glade -

this piece of code

class gui_manage():     def delete_event(self , widget , data):         false         print 'delete'     # #######################     # define functions here      example : start_download(self ,widget)     ########################################     def start_download( self , widget  ):         print 'add_url_clicked'      def __init__(self):         builder = gtk.builder()         builder.add_from_file('gui.glade')         win=builder.get_object('add_url_win')         text_entry= builder.get_object('url_entry')         signals ={           'delete_event' : self.delete_event ,           'destroy' : self.destroy  ,          'cancel_button_clicked' : self.delete_event ,           'addpaused_button_clicked' : self.addpaused ,      'start_download_clicked' : self.start_download ,           'addpaused_button_clicked' : self.addpaused           }         builder.connect_signals(signals) 

the glade file shows corresponding lines:

<object class="gtkbutton" id="start_download">     <property name="label" translatable="yes">start download</property>       <property name="visible">true</property>            <property name="can_focus">true</property>            <property name="receives_default">true</property>       <property name="tooltip_text" translatable="yes">start download ...</property>     <property name="use_action_appearance">false</property> <signal name="clicked" handler="start_download" swapped="no"/>' 

i got error :

gui_manage.py:45: runtimewarning: missing handler 'start_download'   builder.connect_signals(signals) 

however delete_event() method called clicked ' event of cancel button ' successfully.

in brief, methods defined same way, connected in same dictionary, although missing!

it work :

'def start_download( self , object  ):     print 'add_url_clicked'' 

instead of

'def start_download( self , widget  ):     print 'add_url_clicked'' 

&

'self.signals = {}' 

instead of

'signals = {}' 

&

'self.builder.connect_signals(self)' 

instead of

'self.builder.connect_signals(signals)' 

thancks all