Add underscore as a separator in a binary number in Python

Question

I a trying to convert a decimal number into a 17-bit binary number and add underscore as a separator in it. I am using the following code -

id = 18
get_bin = lambda x, n: format(x, 'b').zfill(n)
bin_num = get_bin(id, 17)

The output I am getting is in the form of -

00000000000010010

I am trying to get the following output -

0_0000_0000_0001_0010

How can I get it?

Answer 1

Using good'ol pal, Python's Format Specification Mini-Language

id = 18
width = 17
bin_num = format(id, '0{}_b'.format(width+3))
print(bin_num)
#0_0000_0000_0001_0010

Answer 2

One way:

import textwrap
result = '_'.join(textwrap.wrap(bin_num[::-1], 4))[::-1]

output:

'0_0000_0000_0001_0010'