What's the correct way to convert bytes to a h

Question

What's the correct way to convert bytes to a hex string in Python 3?

I see claims of a bytes.hex method, bytes.decode codecs, and have tried other possible functions of least astonishment without avail. I just want my bytes as hex!

Answer 1

The method binascii.hexlify() will convert bytes to a bytes representing the ascii hex string. That means that each byte in the input will get converted to two ascii characters. If you want a true str out then you can .decode("ascii") the result.

I included an snippet that illustrates it.

import binascii

with open("addressbook.bin", "rb") as f: # or any binary file like '/bin/ls'
    in_bytes = f.read()
    print(in_bytes) # b'\n\x16\n\x04'
    hex_bytes = binascii.hexlify(in_bytes) 
    print(hex_bytes) # b'0a160a04' which is twice as long as in_bytes
    hex_str = hex_bytes.decode("ascii")
    print(hex_str) # 0a160a04

from the hex string "0a160a04" to can come back to the bytes with binascii.unhexlify("0a160a04") which gives back b'\n\x16\n\x04'

Answer 2

Use the binascii module:

>>> import binascii
>>> binascii.hexlify('foo'.encode('utf8'))
b'666f6f'
>>> binascii.unhexlify(_).decode('utf8')
'foo'

See this answer: Python 3.1.1 string to hex