@cashdev 11 December 2019 edited

«What are the addresses involved in this transaction?» using Python **A Bitcoin Cash transaction contains no addresses**, yet whenever we're presented with a transaction in a graphical interface, we always get to see the addresses involved. Let's find a recent transaction in a block explorer:

Tech used I use the python bitcoincash library, in addition I have a full node running that supports the satoshi client RPC interface. In this case Bitcoin Unlimited. https://pypi.org/project/bitcoincash/ How to find the Bitcoin Cash address We need to **derive the addresses from the transaction outputs**. Let's have a look at the above transaction: import bitcoincash.rpc from bitcoincash.core import lx TX_ID = "07cca646b20b27f2e2385bb9ed63663220b80abe8380072973eef078a1d6f51e" rpc = bitcoincash.rpc.Proxy() tx = rpc.getrawtransaction(lx(TX_ID)) print(tx.vout) $ python3 test.py (CTxOut(0.00005299*COIN, CScript( [OPDUP, OPHASH160, x('b1f1ec3aa28f212cdbb32269f33e6d0ecbc8364c'), OPEQUALVERIFY, OPCHECKSIG])),) The `CScript` here is the `ScriptPubKey` of the transaction output. It looks like the most common used script in Bitcoin Cash, the Pay-to-PubKey Hash (P2PKH). Pay-to-PubKey Hash has the standard template `OPDUP OPHASH160 <pubKeyHash> OPEQUALVERIFY OPCHECKSIG`. **And this can be represented as a Bitcoin Cash address.** The python library has a built in function to derive this, continuing the script above: from bitcoincash.wallet import CBitcoinAddress print("Outputs:") for o in tx.vout: print(str(CBitcoinAddress.from_scriptPubKey(o.scriptPubKey))) $ python3 test.py Outputs: bitcoincash:qzclrmp6528jztxmkv3xnue7d58vhjpkfsr4uskz69 But what about the inputs? The transaction pretty much only contains pointers to previous transaction and no other info. So to find the input addresses, we need to fetch the parent transactions to get their `scriptPubKey`. print("Inputs:") for i in tx.vin: prevout = i.prevout prevtx = rpc.getrawtransaction(prevout.hash) script_from_input = prevtx.vout[prevout.n].scriptPubKey print(str(CBitcoinAddress.from_scriptPubKey(script_from_input))) $ python test.py Outputs: bitcoincash:qzclrmp6528jztxmkv3xnue7d58vhjpkfsr4uskz69 Inputs: bitcoincash:qzcnx0z2l9ncs7el5fcwgufv4mrng605ngc8p5csqn Hurray! **Wow! You made it to the end, thanks for reading!** [sponsors]