CrytoPrimitive Python Weekend Hackathon

• https://redd.it/83d3lz
• CryptoPrimitive slack invite. Make sure to check out #weekend-hackathon!

Table of Content

• Purpose
• Todos
• Python Ethereum Development
  • web3py beta (4.x)
  • Populus Development Cycle
    • Part 1-5: Create, compile and test Solidity contracts
    • Part 6: Deploy contract to a local chain (via geth)
    • Part 7: Interacting With a Contract Instance
    • Part 8: Web3.py Console
  • populus deploy contracts to external servers
  • Use CPTools to speed up development
• Ethereum Virtual Machine Security
• Alternatives
  • Truffle Development Cycle

Purpose

Smart contracts should, in theory, make coordination easier.

Then, with Python's strength in rapid prototyping, we could build as we use them. So as I build a given interface, I could, say, open BP with a few keystrokes, and trust that it might get seen within the dev group and taken care of within minutes.

Todos

The focus will be on quickly building Python apps that the participants can use via command-line right away. We will begin by interfacing with the already-written contracts here: Burnable Payments, BurnChat, and CrowdServe. This should be accomplished at a basic level within the first few hours.

After that, the focus of the hackathon will be on making interaction easier and more fluid via Python command line or simple GUI.

Python Ethereum Development

web3py beta (4.x)

brew install python3
pip3 install --upgrade pip
pip install web3 --pre
# - OR -
pip install web3==4.0.0b11 # https://gitter.im/ethereum/web3.py?at=5a98dc0a6f8b4b9946dc1a32
python3

from cli import bp
bp.getBPCount()
bp.getBP(0)

Populus Development Cycle

https://populus.readthedocs.io/en/latest/dev_cycle.html

Part 1-5: Create, compile and test Solidity contracts

brew install python3
pip3 install --upgrade pip

pip install virtualenv
virtualenv myenv
./myenv/bin/pip install web3

# Install following packages to complie https://github.com/ludbb/secp256k1-py
# needed while installing populus
brew install pkg-config libffi autoconf automake libtool openssl

# Needed while finishing populus installation
sudo touch /usr/local/LICENSE
sudo chown "$(whoami)" /usr/local/LICENSE

./myenv/bin/pip install populus
# - OR -
git clone https://github.com/ethereum/populus.git
cd populus
pip install -e . -r requirements-dev.txt

./myenv/bin/populus init

# Install solidiy (solc) to compile solidity souce code
# http://solidity.readthedocs.io/en/develop/installing-solidity.html
brew tap ethereum/ethereum
brew install solidity
./myenv/bin/populus compile

# Test deploy, no need to run before py.test
./myenv/bin/populus deploy --chain tester Donator

# Unit-testing
# py.test required eth-utils 0.7.* version
./myenv/bin/pip install eth-utils==0.7.*
./myenv/bin/pytest

# test selected test file
./myenv/bin/pytest tests/test_project_ownership.py --disable-pytest-warnings

# test selected test-case
./myenv/bin/pytest tests/test_project_ownership.py::test_another_participant --disable-pytest-warnings

More about solidity contract testing using populus at http://populus.readthedocs.io/en/latest/testing.html#web3

Part 6: Deploy contract to a local chain (via geth)

http://populus.readthedocs.io/en/latest/dev_cycle.part-06.html

# install geth
brew tap ethereum/ethereum
brew install ethereum

# init new chain and run
./myenv/bin/populus chain new horton
chains/horton/./init_chain.sh
chains/horton/./run_chain.sh

# deploy contracts to the new chain (--no-wait-for-sync to use dummy Ether to run the transaction immediately)
./myenv/bin/populus deploy --chain horton Donator --no-wait-for-sync

Part 7: Interacting With a Contract Instance

http://populus.readthedocs.io/en/latest/dev_cycle.part-07.html

Populus does not ask you for the address and the ABI of the projects’ contracts: it already has the address in the registrar file at registrar.json, and the ABI in build/contracts.json

./myenv/bin/python3 scripts/donator.py

Part 8: Web3.py Console

http://populus.readthedocs.io/en/latest/dev_cycle.part-08.html

solc --abi contracts/Donator.sol
./myenv/bin/python3 cli/donator.py

populus deploy contracts to external servers

ganache-cli for example

npm install -g ganache-cli
ganache-cli -p 7545

Add following config to "chains": { ... } in project.json

"ganache": {
    "chain": {
      "class": "populus.chain.ExternalChain"
    },
    "web3": {
      "provider": {
        "class": "web3.providers.rpc.HTTPProvider",
      "settings": {
        "endpoint_uri": "http://127.0.0.1:7545"
      }
     }
    },
    "contracts": {
      "backends": {
        "JSONFile": {"$ref": "contracts.backends.JSONFile"},
        "ProjectContracts": {
          "$ref": "contracts.backends.ProjectContracts"
        }
      }
    }
}

./myenv/bin/populus deploy --chain ganache Donator --no-wait-for-sync

Use CPTools to speed up development

Check out https://github.com/cryptoprimitive/CPTools for details

git submodule add https://github.com/cryptoprimitive/CPTools.git cptools
git submodule update

cd cptools
python3

from cptools import cptools
cptools.printNumberedAccountList()
cptools.printUpdates()

Ethereum Virtual Machine Security

See security

Alternatives

Truffle Development Cycle

https://hackernoon.com/ethereum-development-walkthrough-part-2-truffle-ganache-geth-and-mist-8d6320e12269

brew install node
npm i npm to update
npm install -g truffle
# https://ethereum.stackexchange.com/questions/42840/contracts-will-not-compile-using-truffle-with-the-emit-keyword-included-in-fro/42849
npm install -g solc@0.4.21

npm install -g ganache-cli
ganache-cli -p 7545

open migrations/2_deploy_contracts.js
# Add contracts wanted to deploy
truffle migrate --network development
truffle console --network development

Viper Smart Contract Language

https://vyper.readthedocs.io/en/latest/vyper-by-example.html https://www.reggie.io/blog/deploying-ethereum-viper/ https://github.com/ethereum/pyethereum/wiki/Using-pyethereum.tester