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Pyethereum Examples

Python Project Night: Pyethereum And Serpent Programming Guide

Python Project Night: Pyethereum And Serpent Programming Guide

Python Project Night: Pyethereum and Serpent programming guide Let me know if you'd like to speak. I can talk about Pyethereum and Serpent. Where can I learn Serpent, the Python-like language?Specifications: The Serpent Language ( ) Examples: Vitalik's Serpent examples ( ) Tutorials: Pyethereum and Serpent Programming Guide ( ) Videos: Learn Ethereum with Vitalik ( ) Derek will give a 10 minute introduction to Ethereum. Vincent can demo the client and the remainder of the evening will be Open Project Night. 6:15 - 6:30pm: Introduction to the Ethereum project print("Hello and welcome to the Calgary Python local user group ( ).") Check out our website ( )and github for more detailed information. Python project nights are unstructured chances for Python developers to work together, mentor each other, connect socially, teach, learn, or do whatever else it is Python developers want to do together. Come work on Python projects, get programming help, help others, and hang out. Our project nights are great ways to build the Python community, by allowing them to meet and interact in whatever way they find most beneficial. Doors are open from 6-7:30pm. If you arrive late and the front entrance is locked you can try messaging me via Meetup, calling reception, or texting the number at the front entrance. Things to bring: a wireless-enabled laptop and power cord. The official Python tutorial ( ) How to Think Like a Computer Scientist: Learning with Python ( ) An introduction to Python through writing games ( ) Learn Python the Hard Way ( ) Puzzles! ( ) Contribute to an open-source project that uses Python. If you contribute to an open source project that uses Python and want to help new contributors, let us know in a comment! Use Python to participate in space exploration ( ). Unle Continue reading >>

Github - Ethereum/pyethereum: Next Generation Cryptocurrency Network

Github - Ethereum/pyethereum: Next Generation Cryptocurrency Network

This is the Python core library of the Ethereum project. For the python based command line client see: sudo apt-get install libssl-dev build-essential automake pkg-config libtool libffi-dev libgmp-devgit clone pyethereumpython setup.py install Contains the Chain class, which can be used to manage a blockchain. Main methods are: __init__(genesis=None, env=None, new_head_cb=None, reset_genesis=False, localtime=None) - initializes with the given genesis. env specifies the environment (including chain config and database), new_head_cb is a callback called when a new head is added, and localtime is what the chain assumes is the current timestamp. The genesis can be: None - in which case it assumes env is given, and creates a Chain object with the data saved in env.db. If reset_genesis is set, it re-initializes the chain. An allocation (ie. dict {address: {balance: 1, nonce: 2, code: b'\x03\x04\x05', storage: {"0x06": "0x07"}}}) add_block(block) - adds a block to the chain process_time_queue(timestamp) - tells the chain that the current time has increased to the new timestamp. The chain will then process any blocks that were unprocessed because they appeared too "early" get_blockhash_by_number(num) - get the block hash of a block at the given block number get_block(hash) - gets the block with the given blockhash get_block_by_number(num) - equivalent to get_block(get_blockhash_by_number(num)) get_parent(block) - gets the parent of a block get_children(block) - gets the children of a block head (property) - gets the block at the head of the chain state (property) - gets the state at the head of the chain mk_poststate_of_blockhash(hash) - creates a state object after a given block has_block(block) - is that block in the chain? Returns True/False get_chain(from, to) - roughly eq Continue reading >>

Python And Ethereum: Pyethereum/pyethapp

Python And Ethereum: Pyethereum/pyethapp

Written by Ivo van der Wijk on June 9, 2016, 5:04 p.m. For a project I'm working on I want to be able to create smart contracts and transactions from Python. There are several ways to do this, and pyethereum with pyethapp is one of the ways. And since Python is awesome, why not chose a fully Python based solution? Pyethereum is the Python core library for Ethereum. To be honest, I'm not sure what this means and the README isn't very clear either. I assume it provides the basic classes and routines for interacting with Ethereum, but it's unclear if it's capable by itself to download a blockchain and what API it provides. Pyethapp is a "python based client implementing the Ethereum cryptoeconomic state machine", Since it leverages Pyethereum and pydevp2p for p2p networking, I assume that means that by itself Pyethereum won't download the blockchain. So Pyethapp is probably a good choice to start hacking with Python and Ethereum. And then there's Serpent . It's a Python-like language for writing smart contracts. General advise seems to be though to use Solidity in stead since it's the most mature so that's what I'll stick to, even with pyethereum. Installing pyethapp is pretty simple. Just pip install it in a (python2.7) virtualenv. You may need some additional tooling/libraries, I already had those installed. After installing I wanted to connect pyethapp to the testnet because I already have some testing data / ether there, and the download should be much faster than the production network. You can do this by invoking pyethapp as follows $ pyethapp --profile morden --data-dir ../state run Where, in my case, ../state points to a place to store the blockchain data. Pyethapp will look for peers to connect to and while doing this it will spit out confusing warnings. I've lea Continue reading >>

Serpent Tutorials | Ethereum Builder's Guide

Serpent Tutorials | Ethereum Builder's Guide

Let's write our first contract in serpent. Paste the following into a file called "mul2.se": This contract is a simple two lines of code, and defines a function. Functions can be called either by transactions or by other contracts, and are the way that Serpent contracts provide an "interface" to other contracts and to transactions; for example, a contract defining a currency might have functions send(to, value) and check_balance(address). Additionally, the Pyethereum testing environment that we will be using simply assumes that data input and output are in this format. Now, let's try actually compiling the code. Type: > serpent compile mul2.se602380600b600039602e5660003560001a600014156022576020600160203760026020510260405260206040f25b5b6000f2 And there we go, that's the hexadecimal form of the code that you can put into transactions. Or, if you want to see opcodes: > serpent pretty_compile mul2.se[PUSH1, 35, DUP1, PUSH1, 11, PUSH1, 0, CODECOPY, PUSH1, 46, JUMP, PUSH1, 0, CALLDATALOAD, PUSH1, 0, BYTE, PUSH1, 0, EQ, ISZERO, PUSH1, 34, JUMPI, PUSH1, 32, PUSH1, 1, PUSH1, 32, CALLDATACOPY, PUSH1, 2, PUSH1, 32, MLOAD, MUL, PUSH1, 64, MSTORE, PUSH1, 32, PUSH1, 64, RETURN, JUMPDEST, JUMPDEST, PUSH1, 0, RETURN] Alternatively, you can compile to LLL to get an intermediate representation: > serpent compile_to_lll mul2.se(seq (return 0 (lll (seq (def ('double 'x) (seq (set '_temp7_1 (mul (get 'x) 2)) (return (ref '_temp7_1) 32) ) ) ) 0 ) )) This shows you the machinery that is going on inside. As with most contracts, the outermost layer of code exists only to copy the data of the inner code during initialization and return it, since the code returned during initialization is the code that will be executed every time the contract is called; in the EVM you can see this with the CODEC Continue reading >>

Ethereumjs-vm

Ethereumjs-vm

The master branch of this repository has now been updated with the latest Byzantium changes please installdirectly from GitHub if you want to try out the latest VM version and reportissues on our Gitter channel . For a Spurious Dragon/EIP 150 compatible version of this library install thelatest of the 2.2.x series (see Changelog ). code:Buffer.from(code,'hex'),//codeneedstobeaBuffer gasLimit:Buffer.from('ffffffff','hex') To build for standalone use in the browser, install browserify and check run-transactions-simple exsample . This will give you a global variable EthVM to use. The generated file will be at ./examples/run-transactions-simple/build.js. StateTrie - The Patricia Merkle Tree that contains the state. If no trie is given the VM will create an in memory trie. blockchain - an instance of the Blockchain . If no blockchain is given a fake blockchain will be used. blockchain - an instance of ethereumjs-blockchain activatePrecompiles - create entries in the state tree for the precompiled contracts Process blocks and adds them to the blockchain. blockchain - A blockchain that to process cb - The callback. It is given an err parameter if it fails Processes the block running all of the transactions it contains and updating the miner's account. opts.generate - a Boolean; whether to generate the stateRoot. If false runBlock will check the stateRoot of the block against the Trie cb - The callback. It is given two arguments, an error string containing an error that may have happened or null, and a results object with the following properties: receipts - the receipts from the transactions in the block results - an Array for results from the transactions in the block opts.block - The block to which the tx belongs. If omitted a blank block will be used. cb - The callback. It Continue reading >>

Python - How Do I Get Event Log Information From Pyethereum? - Stack Overflow

Python - How Do I Get Event Log Information From Pyethereum? - Stack Overflow

How do I get event log information from pyethereum? I've got some tests that create contracts with pyethereum and do various things with them, but I'm puzzled over how to get information about events they log. from ethereum import tester as ts = t.state()code = """contract LogTest { event LogMyNumber(uint); function LogTest() { } function logSomething() { LogMyNumber(4); } }"""logtest = t.state().abi_contract(code, language='solidity', sender=t.k0)logtest.logSomething()#number_i_logged = WHAT DO I DO HERE?#print "You logged the number %d" % (number_i_logged) No handlers could be found for logger "eth.pow"{'': 4, '_event_type': 'LogMyNumber'} That json that's getting printed is the information I want, but can someone explain, or point me to an example, of how I might capture it and load it into a variable in python so that I can check it and do something with it? There seems to be something called log_listener that you can pass into abi_contract that looks like it's related but I couldn't figure out what to do with it. Continue reading >>

Pyethereum.transactions.transaction.sign

Pyethereum.transactions.transaction.sign

def gen_test(seed): orig_apply_msg = pb.apply_msg apply_message_calls = [] i = 0 def apply_msg_wrapper(_block, _tx, msg, code): apply_message_calls.append(dict(gasLimit=msg.gas, value=msg.value, desgination=msg.to, data=encode_hex(msg.data))) result, gas_rem, out = orig_apply_msg(_block, _tx, msg, code) return result, gas_rem, out pb.apply_msg = apply_msg_wrapper while 1: CODE = gen_random_code(mkrndgen(seed+str(i))) DATA = gen_random_code(mkrndgen(seed+str(i+1))) i += 2 VAL = 0 s = t.state(1) FROM = t.keys[0] FROMADDR = t.accounts[0] TO = t.accounts[1] s.block.delta_balance(TO, 1) pre = s.block.to_dict()['state'] env = { "currentCoinbase": s.block.coinbase, "currentDifficulty": str(s.block.difficulty), "currentGasLimit": str(s.block.gas_limit), "currentNumber": str(s.block.number), "currentTimestamp": str(s.block.timestamp), "previousHash": encode_hex(s.block.prevhash) } apply_message_calls = [] tx = pyethereum.transactions.Transaction(1, 10**12, 10000, TO, VAL, DATA)\ .sign(FROM) msg = pb.Message(FROMADDR, TO, VAL, 10000, DATA) exek = { "address": msg.to, "caller": msg.sender, "code": '0x' + encode_hex(CODE), "data": '0x' + encode_hex(DATA), "gas": str(10000), "gasPrice": str(10**12), "origin": tx.sender, "value": str(VAL) } success, gas, o = pb.apply_msg(s.block, tx, msg, CODE) post = s.block.to_dict()['state'] callcreates = apply_message_calls[1:] if success: break return { "callcreates": callcreates, "env": env, "pre": pre, "post": post, "exec": exek, "gas": str(gas), "out": '0x' + encode_hex(''.join(map(ascii_chr, o))) } Continue reading >>

Introduction To The Python-ethereum Ecosystem

Introduction To The Python-ethereum Ecosystem

Introduction to the Python-Ethereum ecosystem This post is targeted at developers who are interested in getting starteddeveloping on Ethereum using python. It's important to know what you are planning to build because Python may not bethe best choice for certain projects. If you are planning on building a user facing application that will run in abrowser then Python may not be the right choice for you. DApps that run in thebrowser are likely to benifit from a javascript toolchain so you may be betteroff looking into Embark or Truffle . One of the powerful features of a DApp that is written as pure HTML/JS/CSS isthat it can be completely serverless. Choosing python as part of your webtoolchain may anchor your application in the web2 world. Outside of the browser however, Python and Ethereum work very well together. The pyethereum library by VitalikButerin has been the base for most of the tooling that I've written in thePython ecosystem. If what you are looking to write deals with low level EVMinteractions then this library is a great place to start. When you want to actually interact with the blockchain from python you'llprobably want to use JSON-RPC . There are a fewpython client implementations to choose from. These two libraries provide a client for interacting with the JSON-RPCservice over either HTTP or an IPC Socket respectively. They can both act asdrop-in replacements for each other as they expose the same API over adifferent transport layer. To interact with contracts on the blockchain, you'll need to encode and decode the inputs and outputs according to the Ethereum Contract ABI .There are low level tools available for doing this using either ethereum-abi-utils .This library provides the abi encoding and decoding functionality availablefrom within the pyether Continue reading >>

Calling Specific Functions Within A Contract Using Pyethereum

Calling Specific Functions Within A Contract Using Pyethereum

I've been going through this tutorial and got to the part where the contract is being sent to the block chain: {result: da7ce79725418f4f6e13bf5f520c89cec5f6a974, block: 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} It is mentioned that result contains the address of the contract within the block chain. However, I don't understand if it contains the address of the contract, and the contract contains a set of functions how is it possible to call only a subset of it (preferably using pyethereum)? Also, I can't seem to find a pyethtool that has a similar functionality to the one shown in the tutorial. The tutorial you reference is very old in terms of how fast this technology is moving. If you're trying to learn how to create, deploy, and call functions on a contract, I would recommend you look at Solidity and the Web3 API . Although I really like Serpent as well, there's much less documentation making the learning curve a bit steeper. If you want to use Python instead of the Web3 API, you can in fact create and interact with contracts in both Serpent and Solid Continue reading >>

Ethereum Utils Python

Ethereum Utils Python

Utilities Navigataion about; Neat Ethereum tricks. 2 and 2. Ubuntu MATE 16. el6 ethereum. . Im trying to write a python script that can generate a new wallet for that user, import os from ethereum import utils key = utils. module_utils. The regexp parameter allows for a regular expression to find the digits in a string. Version 7 of the Ethereum Alarm Clock GitHub is where people build software. utils. I have top skills in ethereum MYOB MySQL Python Developers in China ready to hire for * developing Linux and cross-platform solutions and utilities. Ethereum ABI Utils. py egg_info failed with error code 1 in Complete output from command python setup File "/private/tmp/pip-sTRicb-build In this python matplotlib tutorial, you will learn how to use this library for making the visualizations to get business insights out of your dataset. iface canvas how to install plugin through the python console apt-get dependency issues. info. start, build bit commands python,Every Day Someone Is Growing Rich form article. 04 LTS 64 bit. knowledge crypto Today. Python en 3. libstoragemgmt-1. I have addons that load icons using the bpy. 6 pyethereum Only Python versions 2. python Edited 5 Years Ago by mike Stack Overflow en espaol Ethereum Data Scripting Tools Batch Utilities Compilers Editors Code web3-utils. 2 and Ubuntu Python C++ Programmers siap untuk mempekerjakan * developing Linux and cross-platform solutions and utilities I have top skills in ethereum Probability And Statistics Utils for Python These are just some classes I wrote to do problems like Dr Ecco's Omniheurist Corner in python They are implemented in C with a python front-end, they are a good 10+ times faster than python-native implementations Branded MMS Coupon Generation with Python and service to distribute branded Continue reading >>

Ethereum Smart Contracts In Python: A Comprehensive(ish) Guide

Ethereum Smart Contracts In Python: A Comprehensive(ish) Guide

Astrophysicist, cofounder of @sempo. Were reinventing disaster response to make it efficient, systematic and transparent. Ethereum Smart Contracts in Python: a comprehensive(ish) guide Its one thing to get a basic smart contract up on Ethereum just google ERC20 Token Tutorial youll find plenty of information on how to do it. Interacting with a contract programmatically is another thing entirely, and if youre a Python coder, then tutorials are scarce. Fortunately for us, Version 4 of Web3.py has just been released, which means its now easier than ever to run a python script and watch as magical things happen on the blockchain. Spooky. A big shout out Piper Merriam , Jason Carver and all the others whove worked so on hard on Web3.py to make life easy for the rest of us at Sempo were using Ethereum to make Disaster Response more transparent, and its only really possible thanks to Web3.py. First we get set up, making sure we have the relevant python libraries installed and so-forth. Python libraries everywhere, but what are theyfor? There are plenty of python libraries related to Ethereum out there, but there are two that come up a lot when people talk about Ethereum: Web3.py and Pyethereum. At first glance its not obvious which one you should use for what. A Python implementation of the Ethereum Virtual Machine (EVM). The EVM, in turn is the part of the Ethereum protocol that actually runs the code in Smart Contracts and determines their outputs. So if you wanted to run an Ethereum node in Python, Pyethereum is a good place to start. Even if youre perfectly happy running your Smart Contracts without running your own node, Pyethereum is still a good library to have around it contains a bunch of functions that do useful things like calculate a users address from their priva Continue reading >>

Pyethereum And Serpent Programming Guide

Pyethereum And Serpent Programming Guide

The content of this tutorial is intended to apply to PoC5. Most of the instructions given below will not work in the older PoC4 implementations of AlethZero (C++) and Ethereal (Go) Over the last few weeks, we have made a large number of changes to the Ethereum protocol. POC4, introducing a large body of changes made by Gavin Wood and myself, was announced as an informal description two weeks ago, and has been formally specified in Gavin Woods yellow paper at . The protocol spec did change substantially, but at the same time things are solidifying; we know why we want transactions to pay fees instead of contracts, so thats not likely to change, we know that code and data will be separate, and the byte-based code and memory and 32-byte-block-based stack and storage are unlikely to change, and we know that the workings of the EVM in general will be similar to what they are now instead of some kind of elaborate Merkle-code-tree construction. POC4 has given myself what I wanted out of Ethereum Script 2 , Gavin a much more optimization-friendly VM architecture, and users a shiny new currency . Meanwhile, Chen Houwu, Heiko Kees and Konrad Feldmeier have taken the lead as our main Python developers, and the networking side of the pyethereum client is getting to the point where it is getting ready to talk to Go and C++. At the same time, aside from all of the managerial tasks that are part and parcel of having a key role in a large project, I have taken it upon myself to bring up to speed the pyethereum VM implementation and the compiler for the HLL programming language. The purpose of this post will be to provide an in-depth technical tutorial into the workings of pyethereum and Serpent, and show you how you can start writing the tools to build your own contracts and applicati Continue reading >>

The Python Ethereum Ecosystem

The Python Ethereum Ecosystem

Given the recent influx of new users to the Ethereum ecosystem it feels appropriate to give an update on the state of Ethereum tools for Python developers. The following tools sit at the top of the python stack, exposing high level interfaces and abstractions for application development and interaction with the Ethereum blockchain. Populus is a smart contract development framework. It can be used as a command line tool to compile and deploy your contracts as well as a python library for high level scripting and automation. The framework also includes tools that make testing your smart contracts simple and painless. Web3.py is a python library inspired by the original Javascript based web3 library. This library exposes a standard and familiar way to interact with the JSON-RPC interface exposed by Ethereum nodes. In addition, it exposes a number of common utilities such as Ethereum currency denomination conversions, a contract class for interacting with smart contracts, and encoding/decoding utilities. Eth-TestRPC: This is the Python implementation of the TestRPC server (not to be confused with the Javascript implementation). This can be run as either a command line tool or programmatically from your code to create a transient Ethereum blockchain that can be used for testing. PyEthApp: PyEthApp sits on top of the PyEthereum library as a full Ethereum node written in python. It has atrophied a bit in the last year due to a lack of active maintenance and development. While I do not believe that this application can be run as a viable full Ethereum node, there is work being done now to fix this. These lower level tools attempt to do one thing well. They are likely to prevent you from re-inventing the wheel as you develop your Ethereum applications. Ethereum Utils: This libr Continue reading >>

Pyethereum - Are There Any Implementations Of Smart Contracts In Python? - Ethereum Stack Exchange

Pyethereum - Are There Any Implementations Of Smart Contracts In Python? - Ethereum Stack Exchange

Are there any implementations of smart contracts in Python? pythereum and pythapp - your question tags - are Python implementations of Ethereum's core library and command line client respectively. They are orthogonal to the language in which smart contracts are written. So the short answer to your question is: no. Having said that, have a look at Serpent: Is it possible to do that though? iivri andre Nov 16 '16 at 22:26 See the other answer from eth. In theory you could write a smart contract in any language you like, but you'd also need to write a compiler. Richard Horrocks Nov 17 '16 at 7:49 Ethereum smart contracts need to compile to EVM (Ethereum Virtual Machine) bytecode. There are no Python to EVM compilers, and for some of the challenges, see What is the merit of creating new smart contract languages like Solidity instead of using other languages? The options are to use a Python-like language Serpent or a recent (Nov 2016) experimental language named Viper . See this for additional information on Viper and Serpent, including their differences. Continue reading >>

Interactive Pyethereum Demo

Interactive Pyethereum Demo

Ethereum development continues to chug along and the python client is now interoperable with the golang and C++ clients. So you can boot up a pyethereum node, download the latest testnet blockchain, and even issue transactions with the API server, but a nice interface for playing with contracts is still lacking. Even with the C++ or golang clients, this can be frustrating, despite the pretty GUI clients. So, lets take advantage of the python interpreter to interactively play with an ethereum blockchain in pyethereum and get a feel for the ethereum Virtual Machine and the pyethereum API. This will also inadvertently give us a handle on building native ethereum apps on top of pyethereum. First thing youll want to do is install a copy of pyethereum. You can go for the official version, but Ive got a clone with some debug flags turned on that are helpful (see processblock.py). Note: we will be using the example contracts provided by Vitalik in serpent/examples. Vitalik also provided an introduction to using pyethereum and serpent back in April, and much of this will be similar to that, but with some more details. So, now that we have pyethereum and serpent installed, lets fire up a python interpreter. I use iPython, mostly because it has tab-completion and lets me explore imported packages really easily (and gives access to function definition and associated documentation). In fact, I figured out most of this tutorial by importing different pyethereum modules in iPython and using tab-completion to explore their innards. If you dont have iPython, a standard python interpreter is fine, just ignore any mention of tab-completion. The focus of this tutorial will be simple contract writing and execution on the blockchain. We need to import the following packages from pyethereum Continue reading >>

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