beem.blockchain module¶
-
class
beem.blockchain.
Blockchain
(steem_instance=None, mode='irreversible', max_block_wait_repetition=None, data_refresh_time_seconds=900)¶ Bases:
object
This class allows to access the blockchain and read data from it
Parameters: - steem_instance (beem.steem.Steem) – Steem instance
- mode (str) – (default) Irreversible block (
irreversible
) or actual head block (head
) - max_block_wait_repetition (int) – (default) 3 maximum wait time for next block is max_block_wait_repetition * block_interval
This class let’s you deal with blockchain related data and methods. Read blockchain related data: .. code-block:: python
from beem.blockchain import Blockchain chain = Blockchain()Read current block and blockchain info .. code-block:: python
print(chain.get_current_block()) print(chain.steem.info())Monitor for new blocks .. .. code-block:: python
- for block in chain.blocks():
- print(block)
or each operation individually: .. code-block:: python
- for operations in chain.ops():
- print(operations)
-
awaitTxConfirmation
(transaction, limit=10)¶ Returns the transaction as seen by the blockchain after being included into a block
Note
If you want instant confirmation, you need to instantiate class:beem.blockchain.Blockchain with
mode="head"
, otherwise, the call will wait until confirmed in an irreversible block.Note
This method returns once the blockchain has included a transaction with the same signature. Even though the signature is not usually used to identify a transaction, it still cannot be forfeited and is derived from the transaction contented and thus identifies a transaction uniquely.
-
block_time
(block_num)¶ Returns a datetime of the block with the given block number.
Parameters: block_num (int) – Block number
-
block_timestamp
(block_num)¶ Returns the timestamp of the block with the given block number.
Parameters: block_num (int) – Block number
-
blocks
(start=None, stop=None, max_batch_size=None, threading=False, thread_num=8)¶ Yields blocks starting from
start
.Parameters: - start (int) – Starting block
- stop (int) – Stop at this block
- mode (str) – We here have the choice between “head” (the last block) and “irreversible” (the block that is confirmed by 2/3 of all block producers and is thus irreversible)
-
get_all_accounts
(start='', stop='', steps=1000.0, limit=-1, **kwargs)¶ Yields account names between start and stop.
Parameters: - start (str) – Start at this account name
- stop (str) – Stop at this account name
- steps (int) – Obtain
steps
ret with a single call from RPC
-
get_current_block
()¶ This call returns the current block
Note
The block number returned depends on the
mode
used when instanciating from this class.
-
get_current_block_num
()¶ This call returns the current block number
Note
The block number returned depends on the
mode
used when instanciating from this class.
-
get_estimated_block_num
(date, estimateForwards=False, accurate=True)¶ This call estimates the block number based on a given date
Parameters: date (datetime) – block time for which a block number is estimated Note
The block number returned depends on the
mode
used when instanciating from this class.
-
static
hash_op
(event)¶ This method generates a hash of blockchain operation.
-
is_irreversible_mode
()¶
-
ops
(start=None, stop=None, **kwargs)¶ Yields all operations (including virtual operations) starting from
start
.Parameters: - start (int) – Starting block
- stop (int) – Stop at this block
- mode (str) – We here have the choice between “head” (the last block) and “irreversible” (the block that is confirmed by 2/3 of all block producers and is thus irreversible)
- only_virtual_ops (bool) – Only yield virtual operations
This call returns a list that only carries one operation and its type!
-
ops_statistics
(start, stop=None, add_to_ops_stat=None, verbose=False)¶ Generates a statistics for all operations (including virtual operations) starting from
start
.Parameters: - start (int) – Starting block
- stop (int) – Stop at this block, if set to None, the current_block_num is taken
:param dict add_to_ops_stat, if set, the result is added to add_to_ops_stat :param bool verbose, if True, the current block number and timestamp is printed This call returns a dict with all possible operations and their occurence.
-
stream
(opNames=[], *args, **kwargs)¶ Yield specific operations (e.g. comments) only
Parameters: - opNames (array) – List of operations to filter for
- start (int) – Start at this block
- stop (int) – Stop at this block
- mode (str) – We here have the choice between “head” (the last block) and “irreversible” (the block that is confirmed by 2/3 of all block producers and is thus irreversible)
The dict output is formated such that
type
caries the operation type, timestamp and block_num are taken from the block the operation was stored in and the other key depend on the actualy operation.
-
wait_for_and_get_block
(block_number, blocks_waiting_for=None, last_fetched_block_num=None)¶ Get the desired block from the chain, if the current head block is smaller (for both head and irreversible) then we wait, but a maxmimum of blocks_waiting_for * max_block_wait_repetition time before failure. :param int block_number: desired block number :param int blocks_waiting_for: (default) difference between block_number and current head
how many blocks we are willing to wait, positive int