ethjsonrpc

Python client for Ethereum using the JSON-RPC interface

• complete: implements all 62 JSON-RPC methods
• provides a high-level interface to create contracts on the blockchain and to call contract methods

Important note

The API is not yet stable, so please use caution when upgrading.

Installation

$ pip install ethjsonrpc

Make sure to have a node running an Ethereum client (such as geth) for the library to connect to.

Example

>>> from ethjsonrpc import EthJsonRpc
>>> c = EthJsonRpc('127.0.0.1', 8545)
>>> c.net_version()
u'1'
>>> c.web3_clientVersion()
u'Geth/v1.3.3/linux/go1.5.1'
>>> c.eth_gasPrice()
50000000000
>>> c.eth_blockNumber()
828948

High-level functionality

These examples assume the following simple Solidity contract:

contract Example {

    string s;

    function set_s(string new_s) {
        s = new_s;
    }

    function get_s() returns (string) {
        return s;
    }
}

Compile it like this:

$ solc --binary stdout example.sol

Setup

>>> compiled = '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'
>>> from ethjsonrpc import EthJsonRpc
>>> c = EthJsonRpc('127.0.0.1', 8545)

Creating a contract on the blockchain

>>> # continued from above
>>> contract_tx = c.create_contract(c.eth_coinbase(), compiled, gas=300000)
>>> # wait here for the contract to be created when a new block is mined
>>> contract_addr = c.get_contract_address(contract_tx)
>>> contract_addr
u'0x24988147f2f2300450103d8c42c43182cf226857'

Calling a contract function with a transaction (storing data)

>>> # continued from above
>>> tx = c.call_with_transaction(c.eth_coinbase(), contract_addr, 'set_s(string)', ['Hello, world'])
>>> tx
u'0x15bde63d79466e3db5169a913bb2069130ca387033d2ff2e29f4dfbef1bc6e0d'

Calling a contract function on the local blockchain (reading data)

>>> # continued from above
>>> results = c.call(contract_addr, 'get_s()', [], ['string'])
>>> results
['Hello, world']

Additional examples

Please see test.py for additional examples.

Implemented JSON-RPC methods

• web3_clientVersion
• web3_sha3
• net_version
• net_listening
• net_peerCount
• eth_protocolVersion
• eth_syncing
• eth_coinbase
• eth_mining
• eth_hashrate
• eth_gasPrice
• eth_accounts
• eth_blockNumber
• eth_getBalance
• eth_getStorageAt
• eth_getTransactionCount
• eth_getBlockTransactionCountByHash
• eth_getBlockTransactionCountByNumber
• eth_getUncleCountByBlockHash
• eth_getUncleCountByBlockNumber
• eth_getCode
• eth_sign
• eth_sendTransaction
• eth_sendRawTransaction
• eth_call
• eth_estimateGas
• eth_getBlockByHash
• eth_getBlockByNumber
• eth_getTransactionByHash
• eth_getTransactionByBlockHashAndIndex
• eth_getTransactionByBlockNumberAndIndex
• eth_getTransactionReceipt
• eth_getUncleByBlockHashAndIndex
• eth_getUncleByBlockNumberAndIndex
• eth_getCompilers
• eth_compileSolidity
• eth_compileLLL
• eth_compileSerpent
• eth_newFilter
• eth_newBlockFilter
• eth_newPendingTransactionFilter
• eth_uninstallFilter
• eth_getFilterChanges
• eth_getFilterLogs
• eth_getLogs
• eth_getWork
• eth_submitWork
• eth_submitHashrate
• db_putString
• db_getString
• db_putHex
• db_getHex
• shh_version
• shh_post
• shh_newIdentity
• shh_hasIdentity
• shh_newGroup
• shh_addToGroup
• shh_newFilter
• shh_uninstallFilter
• shh_getFilterChanges
• shh_getMessages

Reference

• https://github.com/ethereum/wiki/wiki/JSON-RPC