Convert any Bitcoin key prefix to another (e.g.: xpub to ypub, zpriv to Zpriv)

key_converter.py

import hashlib
import base58
import sys

prefix_dict =	{
  "xprv": "0488ade4", # Mainnet - P2PKH or P2SH  - m/44'/0'
  "yprv": "049d7878", # Mainnet - P2WPKH in P2SH - m/49'/0'
  "zprv": "04b2430c", # Mainnet - P2WPKH 	     - m/84'/0'
  "Yprv": "0295b005", # Mainnet - Multi-signature P2WSH in P2SH
  "Zprv": "02aa7a99", # Mainnet - Multi-signature P2WSH
  "tprv": "04358394", # Testnet - P2PKH or P2SH  - m/44'/1'
  "uprv": "044a4e28", # Testnet - P2WPKH in P2SH - m/49'/1'
  "vprv": "045f18bc", # Testnet - P2WPKH         - m/84'/1'
  "Uprv": "024285b5", # Testnet - Multi-signature P2WSH in P2SH
  "Vprv": "02575048", # Testnet - Multi-signature P2WSH

  'xpub': '0488b21e', # Mainnet - P2PKH or P2SH  - m/44'/0'
  'ypub': '049d7cb2', # Mainnet - P2WPKH in P2SH - m/49'/0'
  'zpub': '04b24746', # Mainnet - P2WPKH 	     - m/84'/0'
  'Ypub': '0295b43f', # Mainnet - Multi-signature P2WSH in P2SH
  'Zpub': '02aa7ed3', # Mainnet - Multi-signature P2WSH
  'tpub': '043587cf', # Testnet - P2PKH or P2SH  - m/44'/1'
  'upub': '044a5262', # Testnet - P2WPKH in P2SH - m/49'/1'
  'vpub': '045f1cf6', # Testnet - P2WPKH         - m/84'/1'
  'Upub': '024289ef', # Testnet - Multi-signature P2WSH in P2SH
  'Vpub': '02575483'  # Testnet - Multi-signature P2WSH
}

def convert_key(key, target_prefix):
  decoded_key_bytes = base58.b58decode_check(key)
  target_key_bytes =  bytes.fromhex(prefix_dict[target_prefix]) + decoded_key_bytes[4:]
  return base58.b58encode_check(target_key_bytes)

def main(key, target_prefix):

    if not key or not target_prefix:
        return "Insufficient parameters." 

    if key[1:4] != target_prefix[1:4]:
        return "The key and the target prefix must be both public or both private."

    if not key[:4] in prefix_dict:
        return "Invalid target version."

    if not target_prefix in prefix_dict:
        return "Invalid target version."

    return convert_key(key, target_prefix)

try:
    key = sys.argv[1] 
    target_prefix = sys.argv[2]
    result = main(key, target_prefix)
    print(result)
except IndexError:
    print("Insufficient parameters.")

# For tests:
# zpub6qwqZGWt6Gqm9i2bY2ErmJcTfRHHYX4LeUeszP33bSH3zgNdGiD7LEg57BQp2k5EQ4Qr5UAhgG1DMRSMZSA44UTNy1rLTqa3qaSnT9GmdsF
# xpub6CHJwwB3nukoT7eMsJfcM8RTKUzPfH5LpFcSRbFGqRXHtUkAmPsz67Mo4mVe2vmPanBEaWyakwJ7arDE83L2U16BELTVJ1w5J8KVfyMqtzE
# ypub6X7aFbqxwbJHJQqUhfTEZDWxVT8qbu4qjN8fCz9ADRuAwaZQ243YiB1w5yTE2qRJzRJ3Kza9DbefU8pnqjk3GEmn6g9usvkZZrP94VcBVdz

# yprvAJ8Dr6K57Djz5vm1bdvEC5aDwRJMCSLzN9D4QbjYf6NC4nEFUWjJANhTEghL3npior1TjTXW8vcuiaXoRGH8ZrEBn62qzPxbVKn6x5oY5vq
# xprv9yHxYRe9xYCWEdZtmH8byzUimT9uFpMVT2gqdCqfH5zK1gR2DrZjYK3KDUjk3tAoQCteyyvwgGGMqHvEhZs7mcYaukLRQV97DbiTZSJRaKC
# zprvAcxV9kyzFuHTwDx8RzhrQAfj7PSo94LVHFjHBzdS36k57t3UjAtrnSMbFtev3hUeDV8GUw84bayTbs9N8xh9N5uneRjGaJn5m3qkLdQwiaZ

# python key_converter.py zpub6qwqZGWt6Gqm9i2bY2ErmJcTfRHHYX4LeUeszP33bSH3zgNdGiD7LEg57BQp2k5EQ4Qr5UAhgG1DMRSMZSA44UTNy1rLTqa3qaSnT9GmdsF ypub
# python key_converter.py ypub6X7aFbqxwbJHJQqUhfTEZDWxVT8qbu4qjN8fCz9ADRuAwaZQ243YiB1w5yTE2qRJzRJ3Kza9DbefU8pnqjk3GEmn6g9usvkZZrP94VcBVdz xpub
# python key_converter.py xpub6CHJwwB3nukoT7eMsJfcM8RTKUzPfH5LpFcSRbFGqRXHtUkAmPsz67Mo4mVe2vmPanBEaWyakwJ7arDE83L2U16BELTVJ1w5J8KVfyMqtzE zpub

# python key_converter.py yprvAJ8Dr6K57Djz5vm1bdvEC5aDwRJMCSLzN9D4QbjYf6NC4nEFUWjJANhTEghL3npior1TjTXW8vcuiaXoRGH8ZrEBn62qzPxbVKn6x5oY5vq xprv
# python key_converter.py xprv9yHxYRe9xYCWEdZtmH8byzUimT9uFpMVT2gqdCqfH5zK1gR2DrZjYK3KDUjk3tAoQCteyyvwgGGMqHvEhZs7mcYaukLRQV97DbiTZSJRaKC zprv
# python key_converter.py zprvAcxV9kyzFuHTwDx8RzhrQAfj7PSo94LVHFjHBzdS36k57t3UjAtrnSMbFtev3hUeDV8GUw84bayTbs9N8xh9N5uneRjGaJn5m3qkLdQwiaZ yprv