How Script Type is Detected by Wallets

def classify_script(script: bytes) -> str:
    n = len(script)

    # P2PKH: OP_DUP OP_HASH160 PUSH20 <20 bytes> OP_EQUALVERIFY OP_CHECKSIG
    if (n == 25 and script[0] == 0x76 and script[1] == 0xa9
            and script[2] == 0x14 and script[23] == 0x88 and script[24] == 0xac):
        return "P2PKH"

    # P2SH: OP_HASH160 PUSH20 <20 bytes> OP_EQUAL
    if (n == 23 and script[0] == 0xa9 and script[1] == 0x14 and script[22] == 0x87):
        return "P2SH"

    # P2WPKH: OP_0 PUSH20 <20 bytes>
    if n == 22 and script[0] == 0x00 and script[1] == 0x14:
        return "P2WPKH"

    # P2WSH: OP_0 PUSH32 <32 bytes>
    if n == 34 and script[0] == 0x00 and script[1] == 0x20:
        return "P2WSH"

    # P2TR: OP_1 PUSH32 <32 bytes>
    if n == 34 and script[0] == 0x51 and script[1] == 0x20:
        return "P2TR"

    # P2PK: PUSH33 <33 bytes> OP_CHECKSIG (compressed)
    if n == 35 and script[0] == 0x21 and script[34] == 0xac:
        return "P2PK (compressed)"

    # P2PK: PUSH65 <65 bytes> OP_CHECKSIG (uncompressed)
    if n == 67 and script[0] == 0x41 and script[66] == 0xac:
        return "P2PK (uncompressed)"

    # OP_RETURN: data carrier
    if script[0] == 0x6a:
        return "OP_RETURN (unspendable)"

    return "UNKNOWN / NON-STANDARD"

P2PKH   → Base58Check, version byte 0x00 → "1..." addresses
P2SH    → Base58Check, version byte 0x05 → "3..." addresses
P2WPKH  → Bech32, HRP "bc", version 0   → "bc1q..." (20-byte program)
P2WSH   → Bech32, HRP "bc", version 0   → "bc1q..." (32-byte program)
P2TR    → Bech32m, HRP "bc", version 1  → "bc1p..." addresses

pkh(<key>)                    → P2PKH
sh(multi(2,<k1>,<k2>,<k3>))  → P2SH 2-of-3 multisig
wpkh(<key>)                   → P2WPKH
wsh(multi(2,<k1>,<k2>,<k3>)) → P2WSH multisig
sh(wpkh(<key>))               → P2SH-P2WPKH
tr(<key>)                     → P2TR key path only
tr(<key>,{pk(<k2>),multi_a(2,<k1>,<k2>,<k3>)})  → P2TR with script tree