Talk Outline for Python Web Conf 2022

Blockchain Talk Outline

## Github Repos

- Build a Blockchain: https://github.com/gwenf/build-a-blockchain
- Web3 Code (will be pushed during talk): https://github.com/gwenf/web3-py-blockchain-demo
- Merkle Tree Demo: https://github.com/dlom123/merkle

## Applications

- Metamask (Browser Plugin): https://metamask.io/
- Ganache: https://trufflesuite.com/ganache/index.html
	- For Mac, install Ganache with Homebrew: `brew install --cask ganache`

## Links

- Anders Blockchain Demo: https://andersbrownworth.com/blockchain/hash
- Remix Editor: https://remix.ethereum.org/
- Rinkeby Block Explorer: https://rinkeby.etherscan.io/
- Web3.py: https://web3py.readthedocs.io/en/stable/overview.html
- Eth Brownie: https://eth-brownie.readthedocs.io/en/stable/index.html
- Faucet for test Ether on Rinkeby: https://faucets.chain.link/rinkeby
- Safe Math: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/math/SafeMath.sol

## Build a Blockchain
### Step 1 - Create a Block

1. Create the Block
1. Create a Transaction
1. Populate the Block with Transactions

### Step 2 - Chain the Blocks Together

1. Create Blocks from Transactions
1. Append Blocks to a "Chain" (list)

### Step 3 - Enforce Integrity with Cryptography

1. Hash each block
1. Reference each block's hash in its subsequent block

### Step 4 - Create Nodes

1. Nodes should stay in sync

### Step 5 - Validation

1. Every account has an address (a public key)
2. Transactions can be sent and received between accounts
3. Transactions need to be signed and validated with public-private key pairs
4. Can submit transactions to ledger

### Step 6 - Mining

1. Proof of work (or proof of stake)
1. Mining rewards

### Step 7 - Consensus

1. Longest chain rule

## Web3.py
### Setup
- Install Ganache GUI
- Install Metamask (browser plugin)
- Create new Python project (a new folder with a virtual environment)
- Install python dependencies: `poetry add web3 py-solc-x python-dotenv`

### Step 1 - Interact with Local Blockchain
1. Connect to the local Ganache blockchain
2. Interact with accounts
3. Send and receive transactions

### Step 2 - Learn Browser Tooling & Solidity Overview
1. Test out a contract in the Remix online editor
2. Connect it to Metamask
3. Deploy that contract to Rinkeby

### Step 3 - Deploy a Contract
1. Test out a contract in the Remix online editor
2. Connect it to Metamask
3. Deploy that contract locally to the Ganache blockchain
4. Interact with the contract

### Step 4 - Connect to a live, deployed contract
1. Sign up for an account with Alchemy: https://www.alchemy.com/
2. Copy URL with your key and use it with web3.py
3. Try out connecting to the Crypto Kitty contracts!

## Brownie
### Setup
- Install Ganache-CLI: `npm install -g ganache-cli` (make sure you are using Node version 16 first; if you need to change Node versions, you should use `nvm`)
	- Check Ganache-CLI: `ganache-cli`
- Create a new folder & virtual environment
- Install Brownie: `pip install eth-brownie`

### Step 1
1. Create a new Brownie project: `brownie init`
2. Add our contracts in constracts folder
3. Create `brownie-config.yaml`
4. `brownie compile`
	1. `brownie pm install OpenZeppelin/openzeppelin-contracts@3.0.0`
5. Set up accounts & variables

### Step 2
1. Write a script to deploy the contract
2. Interact with the contract
3. `brownie console`
	1. `accounts[1].balance()`
	2. `accounts[0].transfer(accounts[1], "10 ether")`

### Step 3
1. Switch between test networks
2. `brownie networks list`
3. `brownie run scripts/deploy.py --network rinkeby`
4. Check the deployment of the contract on rinkeby's etherscan

### Step 4
1. Test the contract with Pytest: `brownie test` 
2. Code coverage
	1. `brownie test --coverage`
	2. `brownie gui`

### Step 5 - Brownie Mixes