Part 22: Calculate Account Value Based On Current Market Prices Via API

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. The wallet on Steemit.com shows the account value based on the 3 day moving average of the Steem price and it also assumes that 1 SBD is worth 1 dollar. This tutorial will learn you how to calculate the value of your account based on current market prices for both Steem and SBD.

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Repository

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

What will I learn

• Use Coinmarketcap API to retrieve current market prices
• Retrieve account balances
• Convert VESTS to Steem

Requirements

• Python3.6
• steem-python

Difficulty

• basic

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Tutorial

Setup

Download the file from Github. There is 1 file account_value.py which contains the code. The file takes 1 argument from the command line which sets the account for which the market value will be calculated.

Run scripts as following:
> python account_value.py steempytutorials

Use Coinmarketcap API to retrieve current market prices

Coinmarketcap.com is a popular website that has data for over 1600 different crypto assets including Steem and SBD. There is an API interface which allows for easy access to current market prices.

import json, requests

def get_market_price(token):
    api_url = 'https://api.coinmarketcap.com/v1/ticker/{}/'.format(token)
    response = requests.get(api_url)

    if response.status_code == 200:
        return json.loads(response.content.decode('utf-8'))[0]['price_usd']
    else:
        return None

In order to retrieve the current data for a specific token an API request has to be made. The request is made up out of an url, the syntax that Coinmarketcap uses is as follows https://api.coinmarketcap.com/v1/ticker/<token name>. This will return a json object, which after decoding shows the following:

[{
    'id': 'steem',
    'name': 'Steem',
    'symbol': 'STEEM',
    'rank': '30',
    'price_usd': '3.84594',
    'price_btc': '0.00039802',
    '24h_volume_usd': '15486900.0',
    'market_cap_usd': '977568942.0',
    'available_supply': '254182057.0',
    'total_supply': '271156151.0',
    'max_supply': None,
    'percent_change_1h': '-0.16',
    'percent_change_24h': '-4.08',
    'percent_change_7d': '-5.93',
    'last_updated': '1525448347'
}]

The data for price_usd is contained inside a dict that is inside a list. [0]['price_usd'] will retrieve the data.

Retrieve account balances

Steem-python has a function account.get_balances() that is part of the Account class which can be used to retrieve all account balances for a specific account.

from steem.account import Account

account = Account(str(username), s)

for key, value in account.get_balances()['total'].items():
    if key not in stats:
        stats[key] = value

Running the function will return a dict containing all the balances for the account. To calculate the total account value data under total is needed. Steem Power is listed as VESTS and has to be converted into the Steem Power equivalent.

{
    'available': {
        'STEEM': 11.705,
        'SBD': 1.302,
        'VESTS': 136673.580674
    },
    'savings': {
        'STEEM': 0.0,
        'SBD': 0.0
    },
    'rewards': {
        'STEEM': 0.0,
        'SBD': 0.0,
        'VESTS': 0.0
    },
    'total': {
        'STEEM': 11.705,
        'SBD': 1.302,
        'VESTS': 136673.581
    }
}

Convert VESTS to Steem

To convert VESTS to Steem the ratio between total_vesting_shares and total_vesting_fund_steem has to be calculated and then multiplied with the amount of VESTS. The Steem class contains the function get_dynamic_global_properties that allows this data to be retrieved. The Amount class will be used to make the data usable for calculations.

from steem.amount import Amount

data = s.get_dynamic_global_properties()
total_vesting_shares = Amount(data["total_vesting_shares"]).amount
total_vesting_fund_steem = Amount(data["total_vesting_fund_steem"]).amount
ratio = total_vesting_fund_steem/total_vesting_shares

A lot of useful information about the steem blockchain can be found in this manner. However only total_vesting_shares and total_vesting_fund_steem are needed for this tutorial.

{
    'id': 0,
    'head_block_number': 22139173,
    'head_block_id': '0151d125dd33013110dff3fd612497682ac4cd82',
    'time': '2018-05-04T16:00:15',
    'current_witness': 'smooth.witness',
    'total_pow': 514415,
    'num_pow_witnesses': 172,
    'virtual_supply': '271157259.064 STEEM',
    'current_supply': '267866951.902 STEEM',
    'confidential_supply': '0.000 STEEM',
    'current_sbd_supply': '12921036.227 SBD',
    'confidential_sbd_supply': '0.000 SBD',
    'total_vesting_fund_steem': '191058886.451 STEEM',
    'total_vesting_shares': '389019963857.433024 VESTS',
    'total_reward_fund_steem': '0.000 STEEM',
    'total_reward_shares2': '0',
    'pending_rewarded_vesting_shares': '381908260.635943 VESTS',
    'pending_rewarded_vesting_steem': '186156.473 STEEM',
    'sbd_interest_rate': 0,
    'sbd_print_rate': 10000,
    'maximum_block_size': 65536,
    'current_aslot': 22204805,
    'recent_slots_filled': '340282366920938463463374607431768211455',
    'participation_count': 128,
    'last_irreversible_block_num': 22139156,
    'vote_power_reserve_rate': 10,
    'current_reserve_ratio': 45937724,
    'average_block_size': 16006,
    'max_virtual_bandwidth': '60693185550090240000'
}

Running the script

Running the script will fetch current market prices for Steem and SBD and retrieve the total account balances for Steem, SBD and Steem Power. In the end the dollar value of all assets will be displayed.

python account_value.py steempytutorials
...
Steem/USD: 2.26
SBD/USD: 1.69

Steem: 4.786
SBD: 1.312
Steem Power: 52.874

Dollar value: 132.52

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

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 in conjunction with @amosbastian.