def create_wallet(client: ExonumClient, message_generator: MessageGenerator,
name: str) -> KeyPair:
"""Creates a wallet with the given name and returns a KeyPair for it."""
key_pair = KeyPair.generate()
# Load the "service.proto" from the Cryptocurrency service:
cryptocurrency_module = ModuleManager.import_service_module(
CRYPTOCURRENCY_ARTIFACT_NAME, "service")
# Create a Protobuf message:
create_wallet_message = cryptocurrency_module.TxCreateWallet()
create_wallet_message.name = name
# Convert the Protobuf message to an Exonum message and sign it:
create_wallet_tx = message_generator.create_message(create_wallet_message)
create_wallet_tx.sign(key_pair)
# Send the transaction to Exonum:
response = client.send_transaction(create_wallet_tx)
ensure_status_code(response)
tx_hash = response.json()["tx_hash"]
# Wait for new blocks:
with client.create_subscriber() as subscriber:
subscriber.wait_for_new_block()
subscriber.wait_for_new_block()
ensure_transaction_success(client, tx_hash)
print(f"Successfully created wallet with name '{name}'")
return key_pair
def transfer(
client: ExonumClient, message_generator: MessageGenerator, from_keypair: KeyPair, to_key: PublicKey, amount: int
) -> Tuple[int, int]:
"""This example transfers tokens from one wallet to the other one and
returns the balances of these wallets."""
cryptocurrency_module = ModuleManager.import_service_module(CRYPTOCURRENCY_ARTIFACT_NAME, "service")
# Note that since we are using the Cryptocurrency module,
# we need to load helpers from this module and not from the main module:
helpers_module = ModuleManager.import_service_module(CRYPTOCURRENCY_ARTIFACT_NAME, "helpers")
transfer_message = cryptocurrency_module.Transfer()
transfer_message.to.CopyFrom(helpers_module.PublicKey(data=to_key.value))
transfer_message.amount = amount
transfer_message.seed = Seed.get_seed()
transfer_tx = message_generator.create_message(transfer_message)
transfer_tx.sign(from_keypair)
response = client.send_transaction(transfer_tx)
ensure_status_code(response)
tx_hash = response.json()["tx_hash"]
# Wait for new blocks:
with client.create_subscriber() as subscriber:
subscriber.wait_for_new_block()
subscriber.wait_for_new_block()
ensure_transaction_success(client, tx_hash)
from_balance = get_balance(client, from_keypair.public_key)
to_balance = get_balance(client, to_key)
return from_balance, to_balance
