@doc_metadata(categories=['<STR_LIT>'])<EOL><INDENT>def key_expand(self, key):<DEDENT>
key = self._process_value(key, '<STR_LIT>')<EOL>payload = {"<STR_LIT:key>": key}<EOL>resp = self.call('<STR_LIT>', payload)<EOL>return resp<EOL>
Derive public key and account number from **private key**

:param key: Private key to generate account and public key of
:type key: str

:raises: :py:exc:`nano.rpc.RPCException`

>>> rpc.key_expand(
    key="781186FB9EF17DB6E3D1056550D9FAE5D5BBADA6A6BC370E4CBB938B1DC71DA3"
)
{
  "private": "781186FB9EF17DB6E3D1056550D9FAE5D5BBADA6A6BC370E4CBB938B1DC71DA3",
  "public": "3068BB1CA04525BB0E416C485FE6A67FD52540227D267CC8B6E8DA958A7FA039",
  "account": "xrb_1e5aqegc1jb7qe964u4adzmcezyo6o146zb8hm6dft8tkp79za3sxwjym5rx"
}