#NEWLINE# def evaluate_node( self , node , qn , connection ) : #NEWLINE# #INDENT# values = [ ] #NEWLINE# for child in node . children : #NEWLINE# #INDENT# if hasattr ( child , 'evaluate' ) : #NEWLINE# #INDENT# value = child . evaluate ( self , qn , connection ) #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# value = child #NEWLINE# #UNINDENT# if ( value is not None ) : #NEWLINE# #INDENT# values . append ( value ) #NEWLINE# #UNINDENT# #UNINDENT# return OPERATION_MAP [ node . connector ] ( * values )