Rob E wrote: > On Sat, 15 Sep 2007 03:25:27 +0000, mouseit wrote: > >> I'm trying to add an element to a list which is a property of an >> object, stored in an array. When I append to one element, all of the >> lists are appended! >> >> Example Code: >> >> class Test: >> array = [] >> >> myTests = [Test() , Test() , Test()] >> print len(myTests[1].array) >> myTests[0].array.append( 5 ) >> print len(myTests[1].array) >> >> prints: >> 0 >> 1 >> >> This is probably a really easy question (I'm very new to python), so >> thanks in advance for your help! > > Yes, that's easy: > > class myclass: > var1 = [] > > means that var1 is associated with the class. If you want an attribute: > > class myclass: > def __init__ (self): > self.var1 = [] > > is the correct way. > It's easy to get confused, though, because when you try to access an instance attribute, if the attribute isn't found in the instance the interpreter will then look in the class, and then (if there is one) in the class's superclass, and so on.
A further complication arises with methods, since even when the method is acquired by inheritance it is bound to the instance. >>> class Mine(object): ... pass ... >>> Mine.__init__ <slot wrapper '__init__' of 'object' objects> >>> mine = Mine() >>> mine.__init__ <method-wrapper '__init__' of Mine object at 0x7ff2c3cc> >>> regards Steve -- Steve Holden +1 571 484 6266 +1 800 494 3119 Holden Web LLC/Ltd http://www.holdenweb.com Skype: holdenweb http://del.icio.us/steve.holden Sorry, the dog ate my .sigline -- http://mail.python.org/mailman/listinfo/python-list