I am aware how to convert the private key into WIF format in python, now I am trying to reverse this process and convert a WIF formatted private key back into a 256-bit private key, following this guide: https://en.bitcoin.it/wiki/Wallet_import_format

This is the code to convert from 256-bit private key into WIF format:

import hashlib
import base58
import binascii


private_key_static = "0C28FCA386C7A227600B2FE50B7CAE11EC86D3BF1FBE471BE89827E19D72AA1D"
extended_key = "80"+private_key_static
first_sha256 = hashlib.sha256(binascii.unhexlify(extended_key)).hexdigest()
second_sha256 = hashlib.sha256(binascii.unhexlify(first_sha256)).hexdigest()

# add checksum to end of extended key
final_key = extended_key+second_sha256[:8]

# Wallet Import Format = base 58 encoded final_key
WIF = base58.b58encode(binascii.unhexlify(final_key))

print (WIF)

Now my attempt to reverse this process looks like this:

import hashlib
import base58
import binascii

private_key_WIF = 5HueCGU8rMjxEXxiPuD5BDku4MkFqeZyd4dZ1jvhTVqvbTLvyTJ
first_encode = base58.b58decode(binascii.hexlify(private_key_WIF))
print (first_encode)

Instead of receiving the byte string, I get following error:

TypeError: a bytes-like object is required, not 'str'

(All private keys used are sample keys taken from Bitcoin Wiki.)