def send(self, amount, to_addr):
"""
Send money to the given address from this wallet.
Args:
amount: How much value is sent
to_addr: Address where value is transferred to.
"""
tx = Transaction(self.key)
utxo = self.blockchain.scan_unspent_transactions(
self.key.publickey())
debit = sum(map(lambda x: x['value'], utxo))
change = debit - amount
if change < 0:
raise InsufficientFundsException()
for credit in utxo:
signature = sign(self.key, credit['hash'])
tx.add_in(credit['hash'],
signature, self.key.publickey(), credit['value'])
tx.add_out(amount, to_addr)
tx.add_out(change, self.key.publickey())
self.blockchain.add(tx)
