Question

I’m writing an addon for scapy, and encountered a problem. I had to slightly modify the original scapy code (every class is inheriting from object) The modified code can be found here: http://pastebin.com/pjcL1KJv

The code I wrote is the following:

class Foo():
   array=[ BitField("foo",0x0,2),
           BitField("foo1",0x0,2),
           BitField("bar",0x0,2),
           BitField("blub",None,2)
 ]
def returnArr(a):  
      for i in a.array:
           print type(i.default)


if __name__ == "__main__":
    a=Foo()
    a.blub=0x23
    returnArr(a)

The output:

<
type ‘int’>

<
type ‘int’>

<
type ‘int’>

<
type ‘NoneType’>

My question:
Is it possible to detect if the second paremeter of BitField("foo",0x0,2) is 0x0 or something else? If it is possible, how would I do that? If not, why?

Answer 1

The second parameter is called default, and it’s stored as an attribute also called default.

b = BitField("foo",0x0,2)
b.default   # 0