amm.py from examples not worked

Describe the bug Requires asset (LP) issuer. In the LiquidityPool example, you didn’t have it. /py-stellar-base/example/amm.py

/py-stellar-base/examples#` python3 amm1.py
Liquidity Pool ID: 0aeafb6dda1a3ccc1693a81ffbd0271e8e128d77cc46698fdf1d589c2670e2bd
Traceback (most recent call last):
  File "amm1.py", line 42, in <module>
    .append_change_trust_op(liquidity_pool_asset)
TypeError: append_change_trust_op() missing 1 required positional argument: 'asset_issuer'

CODE

from stellar_sdk import (
    Asset,
    Keypair,
    LiquidityPoolAsset,
    LIQUIDITY_POOL_FEE_V18,
    Network,
    Server,
    TransactionBuilder,
)

horizon_url = "https://horizon.stellar.org/"
#network_passphrase = Network.TESTNET_NETWORK_PASSPHRASE
network_passphrase = Network.PUBLIC_NETWORK_PASSPHRASE

server = Server(horizon_url=horizon_url)
source_keypair = Keypair.from_secret(
    "S*************************************************"
)

# We assume that Hello asset already exists in the Stellar network,
# and you can learn how to issue assets through examples/issue_asset.py
# Here we define a Liquidity Pool Asset.
asset_a = Asset.native()
asset_b = Asset("MERA", "G**************************************7H2A")
fee = LIQUIDITY_POOL_FEE_V18 # tried it with and without
liquidity_pool_asset = LiquidityPoolAsset(asset_a=asset_a, asset_b=asset_b, fee=fee)
#print(liquidity_pool_asset)
liquidity_pool_id = liquidity_pool_asset.liquidity_pool_id
print(f"Liquidity Pool ID: {liquidity_pool_id}")

source_account = server.load_account(account_id=source_keypair.public_key)

# First we need to add a trust line for liquidity_pool_asset.
transaction1 = (
    TransactionBuilder(
        source_account=source_account,
        network_passphrase=network_passphrase,
        base_fee=100,
    )
    .append_change_trust_op(liquidity_pool_asset)
    .set_timeout(30)
    .build()
)
transaction1.sign(source_keypair)
response1 = server.submit_transaction(transaction1)
print(response1)

I tried a lot of things but didn’t work. One final thought: don’t use the append_change_trust_op () wrapper, but use ChangeTrust (). I don’t think that will help.

[minherc]

And thank you very much for your help!

ps: now added these lines to the script: import stellar_sdk print (stellar_sdk .__ version__)

As you would expect, it featured version 5.0.0.

[overcat]

I think you are using 5.0.0 now, you can use pip install stellar-sdk==6.0.0b3 to install 6.0.0b3