Chaning self?

[Miki Tebeka]

Hello,

I'm trying to create a class which is a bit array. I've done the following:
class bitarray(long):
def __init__(self, value):
super(long, self).__init__(value)

def __getitem__(self, index):
if self & (1 << index):
return 1
else:
return 0

def __setitem__(self, index, value):
if value not in (0, 1):
raise ValueError("must be 0 or 1")
if value:
self |= (1 << index)
else:
self &= (~ (1 << index))

However the __setitem__ does not work:

b = bitarray(5)
b[0] 1
b[1] 0
b[2] 1
b[0] = 0
b 5L
b[0]

1

What am I missing?

Thanks.
Miki

 

[Peter Otten]

Subclassing won't work here, because the long type is immutable :-(

Peter