Average difference entropy
By Tim McNamara
Calculating Shannon entropy on octet streams can be confusing, especially with those who lack a background in mathematics. It's also not necessary in many cases. A more intuitive calculation, which is also easier to implement, involves calculating the average difference.
An informal description of the algorithm:
An example implementation in Python:
def entropy(data, encoding=None): if not isinstance(data, bytes): data = bytes(data, encoding=encoding) data = list(data) A =  + data B = data +  diff = [abs(B[i] - A[i]) for i in range(len(data))][1:-1] return sum(diff) / len(diff)