@merc1er 2 January 2020

Python + Bitcoin Cash | Part 2 This article is **part 2** of my introduction to **BitCash**, a Bitcoin Cash software library for the Python programming language. https://ofek.github.io/bit/guide/intro.html#why-bit You can find part 1 here 👍🏻. https://read.cash/@merc1er/python-bitcoin-cash-a61e2bfe#developing-with-bitcoin-is-hard A quick recap Let's refresh our memory with the basic features we saw so far: Import the `Key` class and create a wallet: from bitcash import Key key = Key() Display the address and balance of the wallet (in USD): print(key.address) print(key.get_balance('usd')) Send 10 cents (notice the list of tuples - that is because you can send to multiple addresses at once if you want): key.send([('bitcoincash:qr02vc2t5yr9fe4ujdpkg99d5d0dgxstfqtgxg7umu', 0.1, 'usd')]) Good. Now let's do some more advanced stuff 😎 Now, one major issue is if you close your terminal, **your funds are gone**! We don't want that... Let's see how to backup your private key. Note: the private key is what allows you to spend the coins. If you lose it, the funds are lost. print(key.to_wif()) The `to_wif()` method returns the WIF - the Wallet Import Format. It is a human readable format of the private key. Save this somewhere, and if you accidentally close your terminal or your computer turns off, you can easily recover your wallet like so: https://en.bitcoin.it/wiki/Wallet_import_format recovered_key = Key('YOUR_WIF_HERE') Some examples 👨🏻‍💻 Show pair Let me show you what a basic script with BitCash could be: from bitcash import PrivateKeyTestnet def show_pair(): key = PrivateKeyTestnet() wif = key.to_wif() address = key.address return wif + ' is the private key associated with ' + address print(show_pair()) # returns: # cPQ6D6ad4ejj1xNuH5ApqM3QijtjL3pZwwkEM3Mxdmtts1fmHZtb is the private key associated with bchtest:qq25uvnlvacamvmuqulp2c3k7pgal0x3xucenm9cdv Satoshi's Shotgun ⚠️ We will need to send transactions from now on. I am using the `PrivateKeyTestnet` class instead of `Key` so that I can send testnet coins, which have no value. It is a good practice for learning in order to avoid losing funds ⚠️ Now, a **"Satoshi's Shotgun"**- a script that aims to 'flood' the block chain with a lot of transactions: import time from bitcash import PrivateKeyTestnet KEY = PrivateKeyTestnet('cRxqxzA7HPDzPxWvvE5HGDMZRQYwfwKyoWRzEdHxKREEo93yS4dd') ADDRESS = KEY.address def shoot(): output = [ (ADDRESS, 1000, 'satoshi'), ] KEY.get_unspents() # this refreshes the UTXO set (see part 1) print(KEY.send(output)) def main(tx_count=10): for i in range(tx_count): shoot() time.sleep(2) # sends a transaction every 2 seconds if __name__ == '__main__': main() In this script, we are sending a transaction every 2 seconds (we could do a lot better). Feel free to try it, I left some coins in the wallet. Add data to the block chain ⛓ Every transaction is recorded forever on the block chain. You can also add arbitrary data to a transaction. Let's do that now. In a Python shell, type: from bitcash import PrivateKeyTestnet testnet_key = PrivateKeyTestnet() testnet_key.to_wif() # 'cRxqxzA7HPDzPxWvvE5HGDMZRQYwfwKyoWRzEdHxKREEo93yS4dd' testnet_key.address # 'bchtest:qqt4x47tpvxpxgms3mhck94wujh9p29rmshrh9lqll' testnet_key.get_balance() # 1000000 output = [ ('bchtest:qq0sea6rkxzw8eakxy65rwfftfh3qf97zgnagypgvx', 1000, 'satoshi'), ] testnet_key.send(output, message='I am in the block chain!') # '65e38d77950f2da958aa2132a93d13d78409612a86b6b701dfbff724d473bc82' Boom! `65e38d77950f2da958aa2132a93d13d78409612a86b6b701dfbff724d473bc82` is the transaction ID. Let's see this in a block explorer (link here) https://explorer.bitcoin.com/tbch/tx/65e38d77950f2da958aa2132a93d13d78409612a86b6b701dfbff724d473bc82

Conclusion There is much more you can do with Bitcash (offline transactions, Set your own fee, server integration...) but we have the basics covered. In a next article, would you be interested in learning how to build a Telegram Bitcoin Cash tipping bot with BitCash? Please let me know in the comments 😃