Steps for hex encoding

## Hex encode for 'Hello' is 48656c6c6f. How does this work?
>>> binascii.hexlify(b'Hello')
b'48656c6c6f' (48 65 6c 6c 6f)

## Let's encode the letter 'H'
## First, convert 'H' to ascii code

>>> ord('H')
72

## Next, convert '72' to binary digit

>>> bin(72)
'0b1001000' (01001000)

## Divide '01001000' to two part.

0100 + 1000

## Convert each binary digit to decimal
>>> int('0100', 2)
4
>>> int('1000', 2)
8

4 and 8 = 48

So the hex encode for 'H' is 48.