@doc_metadata(categories=['<STR_LIT>'])<EOL><INDENT>def payment_begin(self, wallet):<DEDENT>
wallet = self._process_value(wallet, '<STR_LIT>')<EOL>payload = {"<STR_LIT>": wallet}<EOL>resp = self.call('<STR_LIT>', payload)<EOL>return resp['<STR_LIT>']<EOL>
Begin a new payment session. Searches wallet for an account that's
marked as available and has a 0 balance. If one is found, the account
number is returned and is marked as unavailable. If no account is
found, a new account is created, placed in the wallet, and returned.

:param wallet: Wallet to begin payment in
:type wallet: str

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

>>> rpc.payment_begin(
... wallet="000D1BAEC8EC208142C99059B393051BAC8380F9B5A2E6B2489A277D81789F3F"
... )
"xrb_3e3j5tkog48pnny9dmfzj1r16pg8t1e76dz5tmac6iq689wyjfpi00000000"