Adding bech32 spending example about python-bitcointx HOT 4 OPEN

  spend_key=None # from privkeyBytes parameter ?
  btc_contract='?'

from bitcointx.wallet import CCoinAddress
from bitcointx.core import CMutableTransaction,CTxIn, CTxOut,COutPoint,lx,CTxInWitness
from bitcointx.core.script import SIGHASH_ALL,SIGVERSION_WITNESS_V0, DATA,CScriptWitness,CBitcoinScript

def sweep_bech32_tx(utxos, toAddrStr, privkeyB, feeSat=200):

  spend_key=None # from privkeyB parameter ?
  btc_contract='?'

  in_amount = sum([amntSat for txid,vout_n,amntSat in utxos])
  out_amount = in_amount - feeSat

  # Create the unsigned transaction.
  tx = CMutableTransaction(
    vin=[CTxIn(prevout=COutPoint(hash=lx(txid), n=vout_n)) for txid,vout_n,amntSat in utxos],

    vout=[CTxOut(nValue=out_amount, scriptPubKey=CCoinAddress(toAddrStr).to_scriptPubKey())]
  )
  cond = b'\x01' # branch_condition true
  # We used P2WSHCoinAddress to create the address that we sent bitcoin to, so we know that we need to use SIGVERSION_WITNESS_V0
  sighash = btc_contract.sighash(tx, 0, SIGHASH_ALL, amount=in_amount, sigversion=SIGVERSION_WITNESS_V0)
  spend_sig = spend_key.sign(sighash) + bytes([SIGHASH_ALL])
  # This is script witness, not script. The condition for OP_IF
  # in our script is directly encoded as data in the witness.
  # We cannot use OP_TRUE/OP_FALSE here. We use DATA guard is to ensure that.
  witness = CScriptWitness([spend_sig, DATA(cond), btc_contract])
  # empty scriptSig, because segwit
  tx.vin[0].scriptSig = CBitcoinScript([])
  # all data to check the spend conditions is in the witness
  tx.wit.vtxinwit[0] = CTxInWitness(witness)
  # VerifyScript not working
  return tx

# inputs: (txid, vout_n, amntSat)
utxos = [
  ('097fed228b1c4afb9dc8df2ae137e4be5e1c1376541c2db3b1c74a6166e7842b', 0, 178876), 
]
tx = sweep_bech32_tx(utxos, toAddrStr='bc1..', privkeyB=bytes.fromhex('11'*32))
print(tx)