JNZ is short for “Jump if not zero (ZF = 0)”, and NOT “Jump if the ZF is set”. If it’s any easier to remember, consider that JNZ and JNE (jump if not equal) are equivalent. Therefore, when you’re doing cmp al, 47 and the content of AL is equal to 47, the ZF is … Read more
For two objects a and b, __cmp__ requires that one of a < b, a == b, and a > b is true. But that might not be the case: consider sets, where it’s very common that none of those are true, e.g. {1, 2, 3} vs {4, 5, 6}. So __lt__ and friends were … Read more
The cmp_to_key method returns a special object that acts as a surrogate key: class K(object): __slots__ = [‘obj’] def __init__(self, obj, *args): self.obj = obj def __lt__(self, other): return mycmp(self.obj, other.obj) < 0 def __gt__(self, other): return mycmp(self.obj, other.obj) > 0 def __eq__(self, other): return mycmp(self.obj, other.obj) == 0 def __le__(self, other): return mycmp(self.obj, other.obj) … Read more