def prepare_transaction(cls,
address,
outputs,
compressed=True,
fee=None,
leftover=None,
combine=True,
message=None,
unspents=None):
"""Prepares a P2PKH transaction for offline signing.
:param address: The address the funds will be sent from.
:type address: ``str``
:param outputs: A sequence of outputs you wish to send in the form
``(destination, amount, currency)``. The amount can
be either an int, float, or string as long as it is
a valid input to ``decimal.Decimal``. The currency
must be :ref:`supported <supported currencies>`.
:type outputs: ``list`` of ``tuple``
:param compressed: Whether or not the ``address`` corresponds to a
compressed public key. This influences the fee.
:type compressed: ``bool``
:param fee: The number of satoshi per byte to pay to miners. By default
Bit will poll `<https://bitcoinfees.21.co>`_ and use a fee
that will allow your transaction to be confirmed as soon as
possible.
:type fee: ``int``
:param leftover: The destination that will receive any change from the
transaction. By default Bit will send any change to
the same address you sent from.
:type leftover: ``str``
:param combine: Whether or not Bit should use all available UTXOs to
make future transactions smaller and therefore reduce
fees. By default Bit will consolidate UTXOs.
:type combine: ``bool``
:param message: A message to include in the transaction. This will be
stored in the blockchain forever. Due to size limits,
each message will be stored in chunks of 40 bytes.
:type message: ``str``
:param unspents: The UTXOs to use as the inputs. By default Bit will
communicate with the blockchain itself.
:type unspents: ``list`` of :class:`~bit.network.meta.Unspent`
:returns: JSON storing data required to create an offline transaction.
:rtype: ``str``
"""
unspents, outputs = sanitize_tx_data(
unspents or NetworkAPI.get_unspent_testnet(address),
outputs,
fee or get_fee_cached(),
leftover or address,
combine=combine,
message=message,
compressed=compressed)
data = {
'unspents': [unspent.to_dict() for unspent in unspents],
'outputs': outputs
}
return json.dumps(data, separators=(',', ':'))
def get_unspents(self):
"""Fetches all available unspent transaction outputs.
:rtype: ``list`` of :class:`~bit.network.meta.Unspent`
"""
self.unspents[:] = NetworkAPI.get_unspent_testnet(self.address)
self.balance = sum(unspent.amount for unspent in self.unspents)
return self.unspents
