The math.log2() function calculates the base-2 logarithm of a number.

math.log2(x)

Where x is the number whose base-2 logarithm we want.

import math

print(math.log2(4))
print(math.log2(8))
print(math.log2(64))
print(math.log2(100))

The math.log2 function is shorthand  for math.log() function with 2 as the base i.e math.log(x, 2)

import math

print(math.log2(50))
print(math.log(50, 2))

ValueError is raised if the value given as argument is negative.

import math

math.log2(-1)