Primitive Types:

In Python, everything is an object, including Booleans, ints, chars

def count_bits(x):
    num_bits = 0
    while x:
        num_bits += x & 1
        x >>= 1
    return num_bits

’»’ and ‘«’ in python is bit operator, it moves the number(binary) to left or right for digits

python3 ints are unbounded

& 与 | 为位上的 and or

2 & 3   ---> 10 & 11 = 10(base 2) = 2 
1 & 0   ---> 10 & 01 = 0 

^ is XOR a 与 b 不一样 — ture a 与 b 一样 — false

2 ^ 3 = 1

~ 按位取反

~8 = 7 

Data Structures - Primitive Types