Bit length of a positive integer in Python

Question

1 = 0b1 -> 1
5 = 0b101 -> 3
10 = 0b1010 -> 4
100 = 0b1100100 -> 7
1000 = 0b1111101000 -> 10
…

How can I get the bit length of an int

Answer 1

Here we can also use slicing.

For positive integers, we'd start from 2:

len(bin(1)[2:])
len(bin(5)[2:])
len(bin(10)[2:])
len(bin(100)[2:])
len(bin(1000)[2:])

which would print:

1
3
4
7
10

For negative integers, we'd start from 3:

len(bin(-1)[3:])
len(bin(-5)[3:])
len(bin(-10)[3:])
len(bin(-100)[3:])
len(bin(-1000)[3:])

which would print:

1
3
4
7
10