PyCardano is a Cardano library written in Python. It allows users to create and sign transactions without depending on third-party Cardano serialization tools, such as cardano-cli and cardano-serialization-lib, making it a lightweight library, which is simple and fast to set up in all types of environments.
Current goal of this project is to enable developers to write off-chain code and tests in pure Python for Plutus DApps. Nevertheless, we see the potential in expanding this project to a full Cardano node client, which could be beneficial for faster R&D iterations.
- Shelly address
- Transaction builder
- Transaction signing
- Multi-asset
- Chain backend integration
- Fee calculation
- UTxO selection
- Native script
- Native token
- Metadata
- Plutus script
- Staking certificates
- Reward withdraw
- Mnemonic
- HD Wallet
- Pool certificate
- Protocol proposal update
- Governance actions
- Byron Address
Install the library using pip:
pip install pycardano
cbor2 is a dependency of pycardano. It is used to encode and decode CBOR data. It has two implementations: one is pure Python and the other is C, which is installed by default. The C implementation is faster, but it is less flexible than the pure Python implementation.
For some users, the C implementation may not work properly when deserializing cbor data. For example, the order of inputs of a transaction isn't guaranteed to be the same as the order of inputs in the original transaction (details could be found in this issue). This would result in a different transaction hash when the transaction is serialized again. For users who encounter this issue, we recommend to use the pure Python implementation of cbor2. You can do so by running ensure_pure_cbor2.sh, which inspect the cbor2 installed in the running environment and force install pure python implementation if necessary.
ensure_pure_cbor2.shhttps://pycardano.readthedocs.io/en/latest/
Expand code
"""Build a transaction using transaction builder"""
from blockfrost import ApiUrls
from pycardano import *
# Use testnet
network = Network.TESTNET
# Read keys to memory
# Assume there is a payment.skey file sitting in current directory
psk = PaymentSigningKey.load("payment.skey")
# Assume there is a stake.skey file sitting in current directory
ssk = StakeSigningKey.load("stake.skey")
pvk = PaymentVerificationKey.from_signing_key(psk)
svk = StakeVerificationKey.from_signing_key(ssk)
# Derive an address from payment verification key and stake verification key
address = Address(pvk.hash(), svk.hash(), network)
# Create a BlockFrost chain context
context = BlockFrostChainContext("your_blockfrost_project_id", base_url=ApiUrls.preprod.value)
# Create a transaction builder
builder = TransactionBuilder(context)
# Tell the builder that transaction input will come from a specific address, assuming that there are some ADA and native
# assets sitting at this address. "add_input_address" could be called multiple times with different address.
builder.add_input_address(address)
# Get all UTxOs currently sitting at this address
utxos = context.utxos(address)
# We can also tell the builder to include a specific UTxO in the transaction.
# Similarly, "add_input" could be called multiple times.
builder.add_input(utxos[0])
# Send 1.5 ADA and a native asset (CHOC) in quantity of 2000 to an address.
builder.add_output(
TransactionOutput(
Address.from_primitive(
"addr_test1vrm9x2zsux7va6w892g38tvchnzahvcd9tykqf3ygnmwtaqyfg52x"
),
Value.from_primitive(
[
1500000,
{
bytes.fromhex(
"57fca08abbaddee36da742a839f7d83a7e1d2419f1507fcbf3916522" # Policy ID
): {
b"CHOC": 2000 # Asset name and amount
}
},
]
),
)
)
# We can add multiple outputs, similar to what we can do with inputs.
# Send 2 ADA and a native asset (CHOC) in quantity of 200 to ourselves
builder.add_output(
TransactionOutput(
address,
Value.from_primitive(
[
2000000,
{
bytes.fromhex(
"57fca08abbaddee36da742a839f7d83a7e1d2419f1507fcbf3916522" # Policy ID
): {
b"CHOC": 200 # Asset name and amount
}
},
]
),
)
)
# Create final signed transaction
signed_tx = builder.build_and_sign([psk], change_address=address)
# Submit signed transaction to the network
context.submit_tx(signed_tx)See more usages under project examples.
There is also a collection of examples under awesome-pycardano.
Click to expand
Clone the repository:
git clone https://github.com/Python-Cardano/pycardano.git
PyCardano uses poetry to manage its dependencies. Install poetry for osx / linux / bashonwindows:
curl -sSL https://install.python-poetry.org | python3 -
Go to poetry installation for more details.
Change directory into the repo, install all dependencies using poetry, and you are all set!
cd pycardano && poetry install
When testing or running any program, it is recommended to enter
a poetry shell in which all python dependencies are automatically
configured: poetry shell.
PyCardano uses pytest for unit testing.
Run all tests:
make test
Run all tests in a specific test file:
poetry run pytest test/pycardano/test_transaction.py
Run a specific test function:
poetry run pytest -k "test_transaction_body"
Run a specific test function in a test file:
poetry run pytest test/pycardano/test_transaction.py -k "test_transaction_body"
We use Coverage to calculate the test coverage.
Test coverage could be generated by: make cov
A html report could be generated and opened in browser by: make cov-html
The package uses Google style docstring.
Code could be formatted with command: make format
The code style could be checked by flake8: make qa
The majority of package documentation is created by the docstrings in python files. We use sphinx with Read the Docs theme to generate the html pages.
Build docs and open the docs in browser:
make docs
If you find this project helpful, please consider donate or sponsor us. Your donation and sponsor will allow us to spend more time on improving PyCardano and adding more features in the future.
You can support us by 1) sponsoring through Github, or 2) donating ADA to our ADA Handle pycardano or to the address below:
addr1vxa4qadv7hk2dd3jtz9rep7sp92lkgwzefwkmsy3qkglq5qzv8c0d
