Python - Integer 到字节 object 最小可能大小

Question

I'm in a special circumstance where I would like to convert an integer into a bytes object of the smallest length possible. I currently use the following method to covert to bytes:

number = 9847
bytes = number.to_bytes(4, 'little')

However I would like to scale that the amount of bytes used down (the 4) to the smallest possible size. How can I achieve this?

Answer 1

I figured it out on my own: I use the following function to do the conversion to bytes for me now:

import math

def int_to_bytes(self, integer_in: int) -> bytes:
    """Convert an integer to bytes"""
    # Calculates the least amount of bytes the integer can be fit into
    length = math.ceil(math.log(integer_in)/math.log(256))

    return integer_in.to_bytes(length, 'little')

This works because with exponents a = b^e is equivalent to e = log(a)/log(b)

In this case our problem is integer_in = 256^e, and we want to solve for e. This can be solved by rephrasing it to e = log(integer_in)/log(256). Lastly, we use math.ceil() to round up the answer to an integer.