PYTHON

Python bytes

>>> (1024).to_bytes(2, byteorder='big')
b'x04x00'
>>> (1024).to_bytes(10, byteorder='big')
b'x00x00x00x00x00x00x00x00x04x00'
>>> (-1024).to_bytes(10, byteorder='big', signed=True)
b'xffxffxffxffxffxffxffxffxfcx00'
>>> x = 1000
>>> x.to_bytes((x.bit_length() + 7) // 8, byteorder='little')
b'xe8x03'

Python bytes

def bit_length(self):
    s = bin(self)       # binary representation:  bin(-37) --> '-0b100101'
    s = s.lstrip('-0b') # remove leading zeros and minus sign
    return len(s)       # len('100101') --> 6