Web3.py

A python implementation of web3.js

Goals

• Python 2.7, 3.4, 3.5 support
• Provide a feature-for-feature python implementation of Web3.js

Installation

pip install web3

API

This documentation is not yet complete, although the API should offer most functionality described in the Javascript API documentation, except for contract events and filters.

Initialisation

Initialising the Ethereum node

# IPC
geth --unlock 0 console

# RPC, if required, with --rpcaddr "localhost" --rpcport <port>
geth --rpc --unlock 0 console

Connecting to the Ethereum node

from web3 import Web3, RPCProvider, IPCProvider

# Initialising a Web3 instance with an RPCProvider:
web3rpc = Web3(RPCProvider(host="127.0.0.1", port="8545"))

# Initialising a Web3 instance with an IPCProvider:
web3ipc = Web3(IPCProvider(ipcpath=None, testnet=False))
# Both arguments can be omitted, the ipcpath should be found automatically

Testing

For testing you can use the TestRPCProvider. This depends on eth-testrpc>=0.2.0 which must be installed independently (It is not included as a hard dependency for this package.)

from web3 import Web3, TestRPCProvider

# Initialising a Web3 instance with an RPCProvider:
web3rpc = Web3(TestRPCProvider())

# or specifying host and port.
web3rpc = Web3(TestRPCProvider(host="127.0.0.1", port="8545"))

The TestRPCProvider uses an EVM backed by the ethereum.tester module from the pyethereum package. This can be quite useful for testing your code which uses web3.py.

Setting defaults

web3.config.defaultAccount = <your (unlocked) account>
web3.config.defaultBlock = "latest"
# Can also be an integer or one of "latest", "pending", "earliest"

Interacting with contracts

abi = "<abi string>"
contractFactory = web3.eth.contract(abi)
contract = contractFactory.at("0xaddress")
# The abi methods should now be available on the contract instance

Timeouts, blocking and nonblocking requests

All function and property requests block by default until the result is available. It is possible to provide an additional keyword argument 'timeout'.

# Blocks indefinitely
>>> web3.eth.getBalance("0xaddress", timeout=None)
23423234

# Blocks until the response is available until the timeout is reached
# returning the response or raising a ValueError with the request id
>>> web3.eth.getBalance("0xaddress", timeout=3) # in seconds
23423234

# Does not block, returns the unique request id immediately
id = web3.eth.getBalance("0xaddress", timeout=0)

# This id can be used to poll the Web3 instance later:
web3.receive(id, timeout=0, keep=False)

# By default, the timeout is 0 and the receive function does not block, returning None if
# the response wasn't available. Otherwise, the timeout argument has the same behaviour
# as a normal call described above.
# Receive will discard the response after the call unless keep is true.

web3

web3.db.*

Available as described in the Javascript API documentation.

web3.eth.*,

Available as described in the Javascript API documentation.

web3.net.*

Available as described in the Javascript API documentation.

web3.personal.*

Available as described in the Javascript API documentation.

web3.ssh.*

Available as described in the Javascript API documentation.

web3.sha3

>>> web3.sha3(b'some text')
'46ba1b442d3606a3437800ee7ae5a0249756405e676739b46aa8f6e85b13fe2b'
>>> web3.sha3('0x80', encoding='hex')
'56e81f171bcc55a6ff8345e692c0f86e5b48e01b996cadc001622fb5e363b421'

web3.eth

web3.eth.iban

>>> web3.eth.iban("XE81ETHXREGGAVOFYORK")
<web3.eth.iban.Iban at 0x107301dd8>

web3.eth.iban.fromAddress

>>> web3.eth.iban.fromAddress('0x00c5496aee77c1ba1f0854206a26dda82a81d6d8').toString()
'XE7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS'

web3.eth.iban.fromBban

>>> web3.eth.iban.fromBban('ETHXREGGAVOFYORK').toString()
'XE81ETHXREGGAVOFYORK'

web3.eth.iban.createIndirect

>>> web3.eth.iban.createIndirect({
...   'institution': "XREG",
...   'identifier': "GAVOFYORK"
... }).toString()
'XE81ETHXREGGAVOFYORK'

web3.eth.iban.isValid

>>> web3.eth.iban.isValid("XE81ETHXREGGAVOFYORK")
True

>>> web3.eth.iban.isValid("XE82ETHXREGGAVOFYORK")
False  # false, cause checksum is incorrect

web3.eth.iban("XE81ETHXREGGAVOFYORK").isValid()
True

web3.eth.iban.isDirect

>>> web3.eth.iban("XE81ETHXREGGAVOFYORK").isDirect()
False

web3.eth.iban.isIndirect

>>> web3.eth.iban("XE81ETHXREGGAVOFYORK").isIndirect()
True

web3.eth.iban.checksum

>>> web3.eth.iban("XE81ETHXREGGAVOFYORK").checksum()
'81'

web3.eth.iban.institution

>>> web3.eth.iban("XE81ETHXREGGAVOFYORK").institution()
'XREG'

web3.eth.iban.client

>>> web3.eth.iban("XE81ETHXREGGAVOFYORK").client()
'GAVOFYORK'

web3.eth.iban.address

>>> web3.eth.iban('XE7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS').address()
'00c5496aee77c1ba1f0854206a26dda82a81d6d8'

web3.eth.iban.toString

>>> web3.eth.iban('XE7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS').toString()
'XE7338O073KYGTWWZN0F2WZ0R8PX5ZPPZS'