Part 24: An In Dept Look At Steem Operation Types Part I

This tutorial is part of a series where different aspects of programming with steem-python are explained. Links to the other tutorials can be found in the curriculum section below. This part is a direct continuation of Part 23: Retrieve And Process Full Blocks From The Steem Blockchain and will go into more detail following operation types: transfer, transfer_to_vesting, withdraw_vesting and convert.

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Repository

https://github.com/steemit/steem-python

What will I learn

• How to access data in a operation
• What is a transfer?
• What is a transfer_to_vesting
• What is a withdraw_vesting
• What is a convert?

Requirements

• Python3.6
• steem-python

Difficulty

• basic

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Tutorial

Setup

Download the files from Github. There 2 are files get_blocks.py which contains the code. The main file takes 3 arguments from the command line which sets the starting_block, block_count and what operation to filter for.

Run scripts as following:
> python get_block.py 22224731 10 transfer

How to access data in a operation

The previous tutorial went into great detail how to extract operations from blocks. There are 19 different operations in total and each has a different structure. However, the data for the operation is always stored in the same spot.

{
    'ref_block_num': 8004,
    'ref_block_prefix': 1744181707,
    'expiration': '2018-05-07T15:29:54',
    'operations': [
        ['vote', {
            'voter': 'acehjaya',
            'author': 'zunaofficial79',
            'permlink': 'kabut-pagi',
            'weight': 10000
        }]
    ],
    'extensions': [],
    'signatures': ['1f205086670c27365738697f0bc7cfde8b6e976608dc12b0d391b2b85ad7870a002313be4b09a358c30010be2a09bebacead866ba180afc348ce40c70566f4ed88']
}

Under operations is an array, the first index is the operation type and the second index is a json table with the operation data.

if transaction['operations'][0][0] == self.tag:
    self.process_operation(transaction['operations']
                           [0][1],
                           self.tag)

Filter for the required operation type and process the json data. For this example tutorial a different class is made for each operation type which stores the data in respective variables and has a print function. These classes can be found in the operations.py file.

What is a transfer?

Every transfer of either Steem or SBD between two different user accounts is a transfer operation. This operation has 4 variables. from is the account that sends the funds, to the receiving account, amount the valuation and which currency, and optionally memo. In which messages can be added.

{
    'from': 'yusril-steem',
    'to': 'postpromoter',
    'amount': '5.000 SBD',
    'memo': 'https://steemit.com/life/@yusril-steem/our-challenges-and-trials-in-life'
}

By using a class to process the operation all the variables can be neatly kept and additional functions can be added as well. Like the print_operation() which allows for easy printing to the terminal. A separate class is made for each of the operations discussed in this tutorial.

class Transfer():
    def __init__(self, operation, block, timestamp):
        self.account = operation['from']
        self.to = operation['to']
        self.amount = operation['amount']
        self.memo = operation['memo']
        self.block = block
        self.timestamp = timestamp

    def print_operation(self):
        print('\nBlock:', self.block, self.timestamp)
        print('Operation: transfer')
        print('From:', self.account)
        print('To:', self.to)
        print('Amount:', self.amount)
        print('Memo:', self.memo)
        print('')

Additional data that normally falls outside the scope of the operation can also be stored in the class. Like the block in which the operation took place and the timestamp of the operation.

What is a transfer_to_vesting

A power up of Steem by a user is known as a transfer_to_vesting and contains 3 variables. from the user account itself, to the receiving account and amount the amount being powered up. This operation locks up the Steem for 13 weeks.

{
    'from': 'flxsupport',
    'to': 'ltcil',
    'amount': '0.719 STEEM'
}

What is a withdraw_vesting

Opposite to a transfer_to_vesting is a withdraw_vesting. When a user initiates a power down the amount of steem power will be powered down in 13 weekly increments. Vested steem power is displayed in VESTS and has to be converted to Steem based on the current conversion rate. This is outside the scope of this tutorial but can be found here. This operation holds 2 different variables. account the user account and vesting_shares the amount of VESTS to be converted to Steem at the time of the operation.

{
    'account': 'bazimir',
    'vesting_shares': '44671.906021 VESTS'
}

What is a convert?

It is possible to convert SBD to Steem on the internal market. This operation assumes that the value of SBD is at $1.0, which may not be true. Always check the external markets before doing such an operation. After 3 days the operation matures and the user will receive the Steem. This operation holds 3 different variables: amount the amount of SBD to be converted, owner the account initiating the conversion and requestid the id for the system to perform the conversion after 3 days.

{
    'amount': '5000.0 SBD',
    'owner': 'steemit',
    'requestid': 1467592156
}

Running the script

Running the script will print the operations, for which the filter has been set, to the terminal starting from the starting_block for block_count amount of blocks. A class object is made for the operation and the build in print_operation() function is called. The data of the operation is printed to the terminal with the additional information of the block in which the operation is contained and the timestamp of the operation.

python get_blocks.py 22224731 10 transfer

Booted
Connected to: https://rpc.buildteam.io
Block: 22224731

Block: 22224731 2018-05-07T15:20:03
Operation: transfer
From: hottopic
To: jgullinese
Amount: 0.001 SBD
Memo: Hello Friend, Your post will be more popular and you will find new friends.We provide "Resteem upvote and promo" service.Resteem to 18.000+ Follower,Min 45+ Upvote.Send 1 SBD or 1 STEEM to @hottopic (URL as memo) Service Active


Block: 22224731 2018-05-07T15:20:03
Operation: transfer
From: minnowbooster
To: msena
Amount: 0.001 SBD
Memo: You got an upgoat that will be done by bycz,greece-lover,hemanthoj,percygeorge,bigdave2250,mexresorts,wanxlol,nickmorphew,thauerbyi,blackbergeron,aziz96,lovlu,utube,lowestdefinition. We detected an open value of 0.0$, worth 0.001 SBD in send and refunding that! Request-Id: 1176288
...
...
...

Curriculum

Set up:

• Part 0: How To Install Steem-python, The Official Steem Library For Python
• Part 1: How To Configure The Steempy CLI Wallet And Upvote An Article With Steem-Python

Filtering

• Part 2: How To Stream And Filter The Blockchain Using Steem-Python
• Part 6: How To Automatically Reply To Mentions Using Steem-Python
• Part 23: Part 23: Retrieve And Process Full Blocks From The Steem Blockchain

Voting

• Part 3: Creating A Dynamic Autovoter That Runs 24/7
• Part 4: How To Follow A Voting Trail Using Steem-Python
• Part 8: How To Create Your Own Upvote Bot Using Steem-Python

Posting

• Part 5: Post An Article Directly To The Steem Blockchain And Automatically Buy Upvotes From Upvote Bots
• Part 7: How To Schedule Posts And Manually Upvote Posts For A Variable Voting Weight With Steem-Python

Constructing

• Part 10: Use Urls To Retrieve Post Data And Construct A Dynamic Post With Steem-Python

Rewards

• Part 9: How To Calculate A Post's Total Rewards Using Steem-Python
• Part 12: How To Estimate Curation Rewards Using Steem-Python
• Part 14: How To Estimate All Rewards In Last N Days Using Steem-Python

Transfers

• Part 11: How To Build A List Of Transfers And Broadcast These In One Transaction With Steem-Python
• Part 13: Upvote Posts In Batches Based On Current Voting Power With Steem-Python

Account Analysis

• Part 15: How To Check If An Account Is Following Back And Retrieve Mutual Followers/Following Between Two Accounts
• Part 16: How To Analyse A User's Vote History In A Specific Time Period Using Steem-Python
• Part 18: How To Analyse An Account's Resteemers Using Steem-Python

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The code for this tutorial can be found on GitHub!

This tutorial was written by @juliank.