python verify slack bot message

slack.py

def verify_slack_msg(msg):
  try:
    slack_signature = msg['headers']['X-Slack-Signature']
    slack_signing_secret = all_secrets.get('SLACK_SIGNING_SECRET', '')
    sig_basestring = f"v0:{msg['headers']['X-Slack-Request-Timestamp']}:{msg['body']}"
    my_signature = 'v0=' + hmac.new(
      bytes(slack_signing_secret, 'latin-1'),
      msg=bytes(sig_basestring, 'latin-1'),
      digestmod=hashlib.sha256
    ).hexdigest()
    print(f"verify_slack_msg: {my_signature} - {slack_signature}")
    return my_signature.lower() == slack_signature.lower()
  except Exception as e:
    print(e)
    return False

have to verify every message from slack, except the init. challenge msg. and the slack doc. sample code is out of date, https://api.slack.com/authentication/verifying-requests-from-slack