Tutorials

Bundle Many Operations

With Steem, you can bundle multiple operations into a single transactions. This can be used to do a multi-send (one sender, multiple receivers), but it also allows to use any other kind of operation. The advantage here is that the user can be sure that the operations are executed in the same order as they are added to the transaction.

A block can only include one vote operation and one comment operation from each sender.

from pprint import pprint
from beem import Steem
from beem.account import Account
from beem.comment import Comment
from beem.instance import set_shared_blockchain_instance

# not a real working key
wif = "5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3"

stm = Steem(
    bundle=True, # Enable bundle broadcast
    # nobroadcast=True, # Enable this for testing
    keys=[wif],
)
# Set stm as shared instance
set_shared_blockchain_instance(stm)

# Account and Comment will use now stm
account = Account("test")

# Post
c = Comment("@gtg/witness-gtg-log")

account.transfer("test1", 1, "STEEM")
account.transfer("test2", 1, "STEEM")
account.transfer("test3", 1, "SBD")
# Upvote post with 25%
c.upvote(25, voter=account)

pprint(stm.broadcast())

Use nobroadcast for testing

When using nobroadcast=True the transaction is not broadcasted but printed.

from pprint import pprint
from beem import Steem
from beem.account import Account
from beem.instance import set_shared_blockchain_instance

# Only for testing not a real working key
wif = "5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3"

# set nobroadcast always to True, when testing
testnet = Steem(
    nobroadcast=True, # Set to false when want to go live
    keys=[wif],
)
# Set testnet as shared instance
set_shared_blockchain_instance(testnet)

# Account will use now testnet
account = Account("test")

pprint(account.transfer("test1", 1, "STEEM"))

When executing the script above, the output will be similar to the following:

Not broadcasting anything!
{'expiration': '2018-05-01T16:16:57',
 'extensions': [],
 'operations': [['transfer',
                 {'amount': '1.000 STEEM',
                  'from': 'test',
                  'memo': '',
                  'to': 'test1'}]],
 'ref_block_num': 33020,
 'ref_block_prefix': 2523628005,
 'signatures': ['1f57da50f241e70c229ed67b5d61898e792175c0f18ae29df8af414c46ae91eb5729c867b5d7dcc578368e7024e414c237f644629cb0aa3ecafac3640871ffe785']}

Clear BlockchainObject Caching

Each BlockchainObject (Account, Comment, Vote, Witness, Amount, …) has a glocal cache. This cache stores all objects and could lead to increased memory consumption. The global cache can be cleared with a clear_cache() call from any BlockchainObject.

from pprint import pprint
from beem.account import Account

account = Account("test")
pprint(str(account._cache))
account1 = Account("test1")
pprint(str(account._cache))
pprint(str(account1._cache))
account.clear_cache()
pprint(str(account._cache))
pprint(str(account1._cache))

Simple Sell Script

from beem import Steem
from beem.market import Market
from beem.price import Price
from beem.amount import Amount

# Only for testing not a real working key
wif = "5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3"

#
# Instantiate Steem (pick network via API node)
#
steem = Steem(
    nobroadcast=True,   # <<--- set this to False when you want to fire!
    keys=[wif]          # <<--- use your real keys, when going live!
)

#
# This defines the market we are looking at.
# The first asset in the first argument is the *quote*
# Sell and buy calls always refer to the *quote*
#
market = Market("SBD:STEEM",
    blockchain_instance=steem
)

#
# Sell an asset for a price with amount (quote)
#
print(market.sell(
    Price(100.0, "STEEM/SBD"),
    Amount("0.01 SBD")
))

Sell at a timely rate

import threading
from beem import Steem
from beem.market import Market
from beem.price import Price
from beem.amount import Amount

# Only for testing not a real working key
wif = "5KQwrPbwdL6PhXujxW37FSSQZ1JiwsST4cqQzDeyXtP79zkvFD3"

def sell():
    """ Sell an asset for a price with amount (quote)
    """
    print(market.sell(
        Price(100.0, "SBD/STEEM"),
        Amount("0.01 STEEM")
    ))

    threading.Timer(60, sell).start()


if __name__ == "__main__":
    #
    # Instantiate Steem (pick network via API node)
    #
    steem = Steem(
        nobroadcast=True,   # <<--- set this to False when you want to fire!
        keys=[wif]          # <<--- use your real keys, when going live!
    )

    #
    # This defines the market we are looking at.
    # The first asset in the first argument is the *quote*
    # Sell and buy calls always refer to the *quote*
    #
    market = Market("STEEM:SBD",
        blockchain_instance=steem
    )

    sell()

Batch api calls on AppBase

Batch api calls are possible with AppBase RPC nodes. If you call a Api-Call with add_to_queue=True it is not submitted but stored in rpc_queue. When a call with add_to_queue=False (default setting) is started, the complete queue is sended at once to the node. The result is a list with replies.

from beem import Steem
stm = Steem("https://api.steemit.com")
stm.rpc.get_config(add_to_queue=True)
stm.rpc.rpc_queue
[{'method': 'condenser_api.get_config', 'jsonrpc': '2.0', 'params': [], 'id': 6}]
result = stm.rpc.get_block({"block_num":1}, api="block", add_to_queue=False)
len(result)
2

Account history

Lets calculate the curation reward from the last 7 days:

from datetime import datetime, timedelta
from beem.account import Account
from beem.amount import Amount

acc = Account("gtg")
stop = datetime.utcnow() - timedelta(days=7)
reward_vests = Amount("0 VESTS")
for reward in acc.history_reverse(stop=stop, only_ops=["curation_reward"]):
            reward_vests += Amount(reward['reward'])
curation_rewards_SP = acc.steem.vests_to_sp(reward_vests.amount)
print("Rewards are %.3f SP" % curation_rewards_SP)

Lets display all Posts from an account:

from beem.account import Account
from beem.comment import Comment
from beem.exceptions import ContentDoesNotExistsException
account = Account("holger80")
c_list = {}
for c in map(Comment, account.history(only_ops=["comment"])):
    if c.permlink in c_list:
      continue
    try:
         c.refresh()
    except ContentDoesNotExistsException:
         continue
    c_list[c.permlink] = 1
    if not c.is_comment():
        print("%s " % c.title)

Transactionbuilder

Sign transactions with beem without using the wallet and build the transaction by hand. Example with one operation with and without the wallet:

from beem import Steem
from beem.transactionbuilder import TransactionBuilder
from beembase import operations
stm = Steem()
# Uncomment the following when using a wallet:
# stm.wallet.unlock("secret_password")
tx = TransactionBuilder(blockchain_instance=stm)
op = operations.Transfer(**{"from": 'user_a',
                            "to": 'user_b',
                            "amount": '1.000 SBD',
                            "memo": 'test 2'}))
tx.appendOps(op)
# Comment appendWif out and uncomment appendSigner when using a stored key from the wallet
tx.appendWif('5.....') # `user_a`
# tx.appendSigner('user_a', 'active')
tx.sign()
tx.broadcast()

Example with signing and broadcasting two operations:

from beem import Steem
from beem.transactionbuilder import TransactionBuilder
from beembase import operations
stm = Steem()
# Uncomment the following when using a wallet:
# stm.wallet.unlock("secret_password")
tx = TransactionBuilder(blockchain_instance=stm)
ops = []
op = operations.Transfer(**{"from": 'user_a',
                            "to": 'user_b',
                            "amount": '1.000 SBD',
                            "memo": 'test 2'}))
ops.append(op)
op = operations.Vote(**{"voter": v,
                        "author": author,
                        "permlink": permlink,
                        "weight": int(percent * 100)})
ops.append(op)
tx.appendOps(ops)
# Comment appendWif out and uncomment appendSigner when using a stored key from the wallet
tx.appendWif('5.....') # `user_a`
# tx.appendSigner('user_a', 'active')
tx.sign()
tx.broadcast()