Decode Base64 string to byte array

Question

I would create a python script that decode a Base64 string to an array of byte (or array of Hex values).

The embedded side of my project is a micro controller that creates a base64 string starting from raw byte. The string contains some no-printable characters (for this reason I choose base64 encoding).

On the Pc side I need to decode the the base64 string and recover the original raw bytes.

My script uses python 2.7 and the base64 library:

base64Packet = raw_input('Base64 stream:')

packet = base64.b64decode(base64Packet )

sys.stdout.write("Decoded packet: %s"%packet)

The resulting string is a characters string that contains some not printable char.

Is there a way to decode base64 string to byte (or hex) values?

Thanks in advance!

Answer 1

You can use bytearray for exactly this. Possibly the binascii module and struct can be helpful, too.

import binascii
import struct

binstr=b"thisisunreadablebytes"

encoded=binascii.b2a_base64(binstr)
print encoded
print binascii.a2b_base64(encoded)

ba=bytearray(binstr)
print list(ba)

print binascii.b2a_hex(binstr)
print struct.unpack("21B",binstr)