Perform Polkadot setKeys tx from python

set_keys.py

import sys, json
from substrateinterface import SubstrateInterface, Keypair
from scalecodec.base import ScaleDecoder, RuntimeConfiguration, ScaleBytes
from scalecodec.type_registry import load_type_registry_preset
import requests

URL = 'wss://fullnode-relay.chachacha.centrifuge.io'

keysencoded = '...your keys from rotate keys here...'


# Decode session keys
RuntimeConfiguration().update_type_registry(load_type_registry_preset("default"))
RuntimeConfiguration().update_type_registry(load_type_registry_preset("polkadot"))
obj = ScaleDecoder.get_decoder_class('Keys', ScaleBytes(keysencoded))
obj.decode()
sessionkeys = obj.value
print('Session keys: ' + str(sessionkeys))


# Submit session keys as validator
with open('./validator_secret') as file:
  validator_secret = file.read().strip()
keypair = Keypair.create_from_mnemonic(validator_secret)

substrate = SubstrateInterface(
  url=URL,
  ss58_format=42,
  type_registry_preset='rococo',
)

call = substrate.compose_call(
  call_module='Session',
  call_function='set_keys',
  call_params=dict(
    keys=sessionkeys,
    proof=''
  )
)

extrinsic = substrate.create_signed_extrinsic(call=call, keypair=keypair)
receipt = substrate.submit_extrinsic(extrinsic, wait_for_inclusion=True)
print('extrinsic_hash', receipt.extrinsic_hash, 'block_hash', receipt.block_hash)